Haematological system Flashcards
What are the red cell indices
Haemoglobin, MCV, WBC
How is the dietary intake and absorption of iron done?
- Dietary iron exists mostly in the insoluble oxidized state (Fe3+ Ferric ion)
- Absorbed in its reduced state (Fe2+ Ferrous ion)
- Ferric reductase = Duodenal cytochrome b (Dcytb)
o Converts Fe3+ to Fe2+ in the intestinal brush border at the apical cell membrane
o Requires acidity in stomach and hence decreased iron absorption in prolonged PPI
usage and atrophic gastritis
Mechanism
method 1: divalent metal transporter (DMT1) transports Fe2+ across cell membrane into the enterocyte
Method 2: heme transport occurs by the heme carrier protein 1 (HCP1): more Fe2+ is further extracted from heme by heme oxygenase 2(HO2)
A proportion of Fe3+ are bound to ferritin and trapped within the cytoplasm of enterocytes without going into the circlation. Ferritin that is iron free is termed apoferritin. Iron bound to ferritin is lost when the epithelial cells are shed from the mucosa during desquamation.
Remaining Fe2+ transported across the basolateral membrane by ferroportin 1 (FPN) and a protien called hephaestin (HP) into circulation. Ferroportin 1 present in macrophages.
What are the types of iron deficiency?
Absolute iron deficiency
* Blood loss
* Decreased iron intake: malabsoprtion, anorexia nervosa
* Decreased iron absorption: gastrectomy, atrophic gastritis
Functional iron deficiency
* EPO stimulation in chronic renal failure: relative iron deficiency for haematopoiesis
Iron sequestration
* Anemia of chronic disease
Causes of anemia (production defect, destruction, sequestration, diluation)
Sequestration (pooling of blood cells): hypersplenism (splenomegaly), portal HT, chronic infections, haematological diseases
Dilution (increase in plasma volume relative to red cell mass): pregnancy, blood loss with fluid resuscitation
What is the history taking for anemia?
What is the PE for anemia?
What is the biochemical tests for anemia?
What are the ddx for anemia and expected results in CBC with DC + reticulocyte count?
How to differentiate iron deficiency anemia and anemia of crhonic disease based on red cell indices, iron profile?
Negative acute phase reactant: serum iron, transferrin
Positive acute phase reactant: ferritin, hepcidin
- Raised ferritin =/= not Fe deficiency anaemia (e.g. in CKD, both deficiency and chronic disease)
- Use of ferritin: Monitoring in (1) repeated transfusion, (2) inflammatory conditions, e.g. rheum/HLH
What information does an iron profile give you in anemia?
How to diagnose thalassemia in anemia?
How to differentiate the types?
What are the tests for hemolytic anemia and the results?
What is the direct and indirect Coombs test used for?
What is the physiology of anemia of chronic disease?
How to classify haemolytic anemia?
What is the etiology of autoimmune hemolytic anemia associated with warm/cold antibodies?
What CBC result for vit B12 and folate deficiency?
megaloblastic anemia
macrocytic anemia = morphological term describing large RBC in peripheral blood and include all anemias with high MCV
How is vit B12 absorption done?
Ingested vit B12 is bound to haptocorrin (transcobalamin I) in the mouth: dissociated in the stomach because of presence of gastric enzymes such as pepsi nand acid
haptocorrin is replaced by intrinsic factor (secreted by gastric parietal cells) of the stomach
Vit B12- intrinsic factor complex attaches to teh receptro cublin on the surface of the epithelial cells of the terminal ileum (ileal mucosa)
Intrinsic factor is absorbed into the bloodstream and bound to transcobalamin II: vit B12 bound to TC-II is taken up by other cells in the body by receptor medaited endocytosis
How is absorption of folate done?
- Folate polyglutamates cleaved by monoglutamates and absorbed in jejunum
- Absorption is both carrier mediated and passive diffusion
- Folate must be reduced to be effective in its biologicacl role in 1C transfer: folate is reduced to dihydrofolate (DHF) –> tetrahydrofolate (THF) –> 5,10 methylene THF –> L-5 methyl THF via series of enzymatic stpes
- Folatae enters cells by binding to a folate receptor known as megalin
What is the storage of vit b12 and folate, if deficient how long will it take to manifest?
Storage of vit B12. Large total body stores = 2-5mg with 1/2 of it stored in liver –> deficiency of vit B12 does not develop for at least 1-2 years or even longer (5-10 years if vit B12 intake ceases)
Storage of folate: small body stores 5-10mg. Deficiency of folate develops rapidly within weeks to months or even more rapidly if demands for folate is increased (e.g. chronic hemolytic anemia)
What are the functions of vit b12 and folate
DNA synthesis/RNA synthesis/DNA methylation
* Deficiency can casue a cell to arrest in DNA synthesis (S phase) of cell cycle, makes errors in DNA replication and undergo apoptotic death
* Principle action of vit B12: cofactor in recycling 5-methyl THF back to THF which can then be converted to frms that can act as 1-C donros
* Princple action of folate: supply methyl groups that are added to other molecules (i.e. act as a 1C donor)
* 1C metabolism is used in synthesis of purines and pyrimidines used for DNA synthesis. Purine = 10 formyl THF donates 2-methyl groups for purinre synthesis. Pyrimidine = 5,10-methylene THF donates 1 methyl group to convert dUMP into dTMP
Haematopoiesis
Megaloblastic changes: caused by slowing of nuclear division cycle relative to cytoplasmic maturation cycle. Macrocytic RBC and hypersegmented neutrophils are classical findings on peripheral blood smear
Ineffective erythropoiesis: premature death of developing erythropoietic precursor cells in the bone marrow (phagocytosis), evidence of hemolysis including elevated indirect bilirubin, LDH and low haptoglobin
Neuronal function
Vit B12 deficiency = subacute combined degeneration of cord
Degeneration of dorsal and lateral columns of spinal cord due to demyelination
Reduced methylation of neuronal lipids and proteins such as myelin basic protein can lead to demeyelination
Folate deficiency = neural tube defect. Periconceptual or 1st trimester folic acid supplementation decreases occurence of neural tube defects by >70%.
What are the causes of vit B12 deficiency?
- Pernicious anemia
- Inadequate dietary intake: strict vegetarians (that dont consume fortified food but rare (as all carbs are fortified)
- H.pylori infection/gatritis: bacteria elicitc antibodies that cross react with gastric parietla H+K+ ATPase due to molecular mimicry
- Intestinal malabsorption: IBD, pancreatic insufficeincy, fish tapeworm infection
- Gastrectomy/bariatric surgery: absence of gastric acid and pepsin results in impaired liberation of vit b12 from food proteins. Reduced production of intrinsic factor impairs vit B12 absorption
- Extensive ileocecectomy (distal ileum no absorption of vit b12)
- Drug induced
PPI/H2 antagonists/antacids: medications that reduce gastric acid may decrease vit b12 absorption since gastric acid plays a role in dissociation of vit B12 from food proteins which allows it to bind intrinsic factors
Metformin: decreased vit B12 absorption in the ileum due to effects of metformin on Ca2+ dependent membrane action (absorption of vit B12-IF complex is calcium dependent)
What are the casues of folate deficiency?
- Inadequate dietary intake: nearly impossible (unless chronic alcohlism, anorexia nervosa and reduced oral intake)
- Intestinal malabsorption: surgery (gastric bypass), IBD
- Increased folate requirements: pregnancy, chronic hemolytic anemia, exfoliative skin diseases, haemodialysis
- Drug induced: methotrexate (folate antagonist), antibioics (trimethoprim inhibits DHFR), anticonvulsants (valproate/carbamazepine/phenytoin)
What are the clinical manifestations of vit b12 or folate deficiency?
- Anemia and jaundice: combined anemia and jaundice (due to hemolysis)
- Glossitis/angular cheilitis/mouth ulcers. Glossitis presents with pain, swelling and loss of papillae of the tongue occurs in vit B12 deficiency. Mouth ulcers occurs in folate deficiency
- Neuropsychiatric symptoms: presents in both vit B12 and folate deficiency but most of the findings are commonly ascribed in vit b12 deficeincy
Subacute combined degeneration of cord - Presents as slowly progressive weakness, sensory ataxia and paresthesias and ultimately spasticity, paraplegia and incontinence. Not all patients with neurologic abnormalities will have anemia or macrocytosis and thus absence of haematological changes cannot be used to exclude dx
What are the biochemical tests for suspected folate or vit b12 deficiency?
- CBC with DC: macrocytic anemiae with MCV>100fL, low reticulocyte count, mild leukopenia or thrombocytopenia
- Peripheral blood smear: macroovalocytes, hypersegmented neutrophils
- Serum vit b12 level
- Serum holotranscobalamin level (better)
- Serum and RBC folate level: normal level of serum folate is >4ng/mL
- Not routine is methylmalonic acid and homocysteine. Reserved when results for vit B12 and folate levels are borderlines or inconclusive. MMA elevated in vit b12 deficiency but not folate since vit B12 is a cofactor in conversion of methylmalonyl CoA in succinyl CoA
- Serum autoantibodies: anti gatric parietal cell antibody, anti intrinsic factor antibody (both have high specificity but low sensitivity)
Evidence of hemolysis (premature destruction of developing RBCs in bone marrow (intamedullary hemolysis) and peripheral circulation (hemolysis)
* Increased AST
* Increased unconjugated bilirubin
* Increased LDH level
* Increased methemoglobin: oxidized form of Hb inserum which occurs in intravascular hemolysis giving serum a brownish color
* Decreased haptoglobini: free hb binds to haptoglobin in which the haemoglobin-haptoglobin complex is rapidly removed by the liver leading to a reduction in plasma haptoglobin
What is treatment for vit b12 and folate deficiency?
Vit b12 deficiency
* Parenteral admin (dont have capacity to absorb oral replacement i.e. pernicious anemia. symptomatic anemia/neurological findings in which absorption is ensured
Cyanobalamin 1000mcg 1x/week until deficiency corrected and then 1x/month
* Oral admin: cyanobalamin 1000mcg1x/day
Treatment of folate deficiency
* Oral admin: folic acid 5mg 1x/day for folate deficiency. Usually sufficient even if malabsorption is present it is considerable in excess of the 200mcg recommended dietary allowance.
* Folid acid 0.4mg (400mcg) 1x/day for pregnancy
Define neutropenic fever?
- ANC ≤ 500/ μL (AND)
o Single oral temperature ≥ 38.3oC (OR)
o Persistent temperature ≥ 38.0oC sustained over ≥ 1 hour
What are the pathogens causing neutropenic fever?
Bacterial pathogens: S. epidermidis is most common. P. aeruginosa also common
Viral pathogens: human herpes virus common in high risk patients with chemotherapy induced mucositis
* Reactivation of HSV1 and HSV2 (herpes simplex)
* Reactivation of VZV (herpes zoster)
* Reactivation of CMV/EBV and HHV can also occur in patients as a result of immunosuppression or reciept of blood products or stem cells
Fungal pathogens: candida and aspergillus
Candida: acquired through GIT colonization and translocation across damaged intestinal epithelail surface
Candida albicans: C. glabrata, C. tropicalis account for the remainder
Aspergillus species: acquired through inhalation of airborne spores into upper and lower respiratory tract followed by germination and invasive hyphal growth. Aserpgillus common fungal cause in immunocompromised hosts
Primarily affects the upper resiratory tract (sinusitis) and pneumonia but also invovles CNS, bones and skin
What is the pathogenesis of neutropenic fever?
- Chemotherapy/RT induced mucositis of GIT: mucositis through GIT leading to seeding of endogenous flora in the GIT throughout the bloodstream occurs in majority of cases. Neutropenia usually occurs 10-14 days post CT
- Immune defect associated with malignancy
- Presence of indwelling catheters
- Obstruction: obstruction to lymphatic, biliary tract, bronchial, GI or urinary ssytem. Secondary to tumor or result of surgical procedures
What history taking and PE for neutropenic fever?
Detailed examination with emphasis on sites most likely infected including skin, oral cavity, lungs, abd, perianal areas, catheter and biopsy sites
Vital signs and evidence of sepsis: BP/pulse/ temp/RR/GCS. Ill looking, mental obtundation or decreased oral intake suggests sepsis
Specific examination on different organs
* IV catheter sites: erythema and tenderness suggesting infection (must exclude line sepsis)
* Lungs: signs of pneumonia
* Abd: abd tenderness or peritoneal signs may represent neutropenic enterocolitis or C.difficile colitis
* Perianal area: erythema, pain and tender hemorrhoids suggesting infection (avoid DRE which can introduce infection by traumatizing the fragile mucosa)
* Skin and mucous membranes: evidence of rash or mucositis (ask for diarrhea for potential GI mucositis introducing infection)
What Ix for neutropenic fever?
- CBC
- Electrolyte profile (sepsis)
- LFT
- RFT
- Samples for culture and sensitivity test
Blood culture (2 sets from peripheral and central venous catheter if present)
Stool for C.difficile antigen detection or PCR
Urine/sputum/skin lesions/CSF/ peritoneal fluid
Radiological tests
* CXR
* CT thorax/sinus/abdomen/pelvis
Patients with symptoms suggestive of neutropenic enterocolitis or C.difficile colitis should undergo abd CT scan with IV and oral contrast
What is the treatment for neutropenic fever
Environmental precautions: reverse barrier isolation. HSCT recipients should be placed in rooms with positive pressure and high efficiency particular air (HEPA) filtration
Neutropenic diet: low bacterial or low microbial diet consisting of well cooked food, often instituted but may not reduce occurence of infection/fever
Risk stratification
Low risk: expected to be neutropenic <7days and who have no active comorbidities or evidence of hepatic or renal dysfunction
High risk: expected to be neutropenic for >7days and have comorbidities or evidence of hepatic or renal dysfunction
Duration of therapy
Known source = complete standard course of 14 days
Unknown source: continue antibiotics until afebrile and ANC >500cells/uL
medical treatment
Empirical
PO for low risk patients: amoxicillin clavualnate + ciprofloxacin/levofloxacin
IV for high risk patients (must cover for P. aeruginosa (gram-ve, facultative anaerobe): meropenem/ imipnem/ piperacillin/tazobactam
Addition of antifungal agents: should be initated for neutropenic fever after 4-7 days. Liposomal amphotericin B/caspofungin/voriconazole/posaconazole
What is the pathogenesis of DIC?
Widespread activation of coagulation
* Intravascular formation of fibrin
* Thrombotic occlusions of small vessels
* Leads to multiple organ failure
Depletion of platelets and clotting factors
* Widespread intravascualr coagulation and secondary fibrinolysis
* Consumption of clotting factors, inhibitors of coagulation and platelets
* Leads to severe bleeding
What Ix and results for acute DIC/chronic DIC?
What are the causes of DIC?
What is treatment of DIC?
Principle: precipitating trigger must be eliminated before treatment of DIC is effective. Control of bleeding with frequent monitoring of coagulation screen is essential
Platelet and fresh frozen plasma (FFP): supportive therapy
Anticoagulants not favaroable
Antithrombin concentrate not favorable
What is the classification of ITP?
Primary ATP: acquired thrombocytoepnia due to autoimmune platelet destruction in the absence of causes or disorders
3 phases
* newly diagnosed ITP = within 3 months from dx
* Persistent ITP = ongoing ITP between 3-12 months
* Chronic ITP = ITP lasting> 12 months
Secondary ITP
* ITP associated with an underlying condtion most commonly: HIV, HCV, SLE + CLL
* Infections: HIV/HCV/ CMV/VZV/H.pylori
* Autoimmune: SLE/antiphospholipid syndrome/ evans sydnrome (AIHA +ITP)
* Lymphoproliferative disorders = CLL
* Vaccination side effects
* Common variable immune deficiency (CVID)
Drug induced immune thrombocytopenia
* Result of drug dependent platelet antibodies that cause platelet destruction
* Should be distinguished from drug induced bone marrow suppression which is a non-immune related phenemenon
What is the ddx for immune thrombocytopenia?
Congenital platelet disorders
Thrombocytipenia (quantitative)
* Bernard soulier syndrome
* Wiskott aldrich syndrome: considered in young males with thrombocytopenia and small platelets particularly if there is a history of eczema and recurrent infection
* Inherited bone marrow failure syndrome. Congenital anasplastic anemia: fanconi anemia, Schwachman-Diamond syndrome, dyskeratosis congenita
Platelet function disorder (qualitative)
* Defects of adhesion: Bernard Soulier syndrome
* Defects of degranulation: grey platelet syndrome/storage pool disease
* Defects of aggregation: Glanzmanns thromasthenia
Acquired platelet disorders
Thrombocytopenia (quantitative)
Decreased production from bone marrow
* Acquired aplastic anemia
* MDS
* Bone marrow infiltration: leukemia/lymphoma
* Chemotherapy/RT
Increased destruction
Immune related
* ITP
* SLE
* Drug induced thrombocytopenia
Non immune related
* TTP (thrombotic thrombocytopenic purpura)
* Haemolytic uremic syndrome (HUS)
* DIC
* Hypersplenism
Platelet function disorder (qualitative)
* Liver disease
* Uremia
* Drug induced platelet dysfunctino
COX inhibitor: aspirin
GP2b/3a inhibitor: abciximab/tirofiban/eptifibatide
ADP receptor antagonist: clopidogrel/prasugrel/ticlopidine
What is the different presentation of platelet and coagulation disorders?
What is the pathogenesis of immune thrombocytopenia?
Reduced platelet lifespan by antibody mediated destruction
Impaired platelet production
Inciting events
Infection: some cases of ITP associated with a preveding viral infection such as HIV and HCV
Immune alteration
Alteration in immune haemostasis might induce loss of peripheral tolerance and promote development of self reactive antibodies e.g. SLE and CLL
Antibody production: specific IgG autoantibodies produced by patients B cells directed against platelet membrane glycoprotien such as GP2b/3a
What are the SS of immune thrombocytopenia?
Major are asymptomatic
Bleeding
* Result of thrombocytopenia and typically occurs in skin or mucous membrane
* Petechiae: flat, red, discrete lesions that do not blanch under pressure. Occurs in depedent areas of body such as lower legs in ambulatory patients and sacral area in recumbent patients
* Purpura: purpura on skin as dry purpura –> not serious. Purpura on mucous membrane are wet purpura and is a predictor of more serious bleeding
* Epistaxis: minimal epistaxis occuring during nose blowing is common. Continuous epistaxis that requires intervention is a predictor of more serious bleeding
* Hemorrhage: intracranial hemorrhage, overt GI bleeding and haematura is uncommon
How to make dx of ITP (immune thrombocytopenia)?
Diagnosis of ITP is one of exclusion
* Isolated thrombocytopenia (without anemia or leukopenia) without another apparent cause
* Presumptive dx of primary ITP when history, PE and lab testing include peripheral blood smear do not reveal with other potential etiology for thrombocytopenia
* Presumptive dx of secondary ITP when patient with ITP has underlying associated condition such as HIV, HCV, SLE and CLL
What biochemical tests done for immune thrombocytopenia?
- CBC with DC: thrombocytopenia which varies from mild (100-150x10^9/L) to severe (<10 x10^9/L)
Absence of other haematological findings. Evans syndrome = AIHA + ITP - Clotting profile: evaluate for other treatable causes of thrombocytopenia
- Peripheral blood smear: required to confirm that thrombocytopenia is not artifactual due to platelet clumping. ITP not characterized by abnormal platelet morphology
- Anti platelet antibodies: generally not useful but done in QMH
- Serum complements C3/4 levels
- Serum autoimmune markres: ANA/RF/antiphospholipid antibodies
- Viral serology (HBV/HCV/HIV/EBV) and parvovirus B19/CMV PCR +H.pylori antibody. All patients are tested for HIV and HCV because thrombocytopenia is a common presenting finding for these conditions
Bone marrow exam: not routine. Indicated in patients with other unexplained cytopenia, dysplasia on peripheral blood smear
Demonstrate normal cellularity, and normal erythropoiesis and myelopoiesis
What is the history taking of immune thrombocytopenia?
HPI
Bleeding symptoms
* Subcutaneous bleeding such as petechiae, purpura, ecchymosis
* Mucosal bleeding such as epistaxis, gum bleeding and menorrhagia
* Intraaritcular or intramuscular bleeding such as haemarthrosis or muscle haematoma
Medical history
* HIV + HCV +SLE and CLL
* Hypersplenism
* Liver diseases
* History of platelet or coagulation disorers
FH: platelet/coagulation disorders
DH: medication that can cause drug induced thrombocytopenia. Heparin induced thrombocytopenia (HIT)
What is the treatment of immune thrombocytopenia?
General approach
Dx of ITP does not imply therapy is needed
Indications to start treatment
* Platelet count <10x10^9/L
* Clinical evidence of bleeding including mucosal bleed with platelet count 10-30x10^9/L: nose bleeding that cannot be stopped for >15mins, oral mucosal bleeding including gum bleeding or blood retention cyst, GI bleeding
* Severe bleeding regardless of platelet count: intracranial hemorrhage (ICH), retinal hemorrhage
ITP and surgery: platelet count >50x10^9/L is considered safe for minor procefdures
Medical treatment
* Platelet transfusion ineffective in ITP (only emergency situation)
* IVIG is 1st lin therapy: induces a rapid rise of platelet count within 24-48 hours but effect is transient lasting only for 1-2 weeks. Increases platelet count by interfering with macrophage uptake of autoantibody coated platelets
Infuse the drug gradually (5ml/15min; than 10ml/min…) and give it over 1-2 days rather than 4 days
* Corticoisteroids is 2nd line therapy for ITP: must perform bone marrow aspirate to rule out leukemia before starting
* Anti RH(D): alternative to conventional IVIG for patients whose RBC is Rh (D) +ve
* Other treatment options: rituximab, (anti CD20), azathioprine/ cyclosporine/cyclophosphamide/mycophenolate mofetil
Surgical treatment
* Splenectomy (requires immunization for encapsulated organisms)
* Indications: when disease is refractory to steroid, relapse after responding to steroid. High dose of steroids is required for maintenance of safe platelet count.
What is normal platelet lifespan?
in ITP?
Lifespan of platelet is normally about 10 days
* Reduced to 1 – 2 days in immune thrombocytopenic purpura (ITP)
What can be the ddx for ITP?
All causes of bone marrow failure
* Acute leukemia
* Aplastic anemia
* Myelodysplastic syndrome (MDS)
* Bone marrow infiltration by neoplastic disease
All causes of increased platelet consumption
* Hypersplenism
* DIC
* TTP
What is expected bone marow biopsy findings in ITP?
Increased megakaryocytes
* Suggests a consumptive cause of thrombocytopenia
What are the useful investigations for exclusion of DIC?
Peripheral blood film
* Fragmented red cell
Clotting profile
* ↑ PT and APTT
* ↑ D-dimer
* ↓ Fibrinogen level
What are the indications for splenectomy in ITP?
Splenectomy is indicated if
* Disease is refractory to steroid
* Relapse after responding to steroid
* High dose of steroids is required for maintenance of safe platelet count
What are the features of thrombotic thrombocytopenic purpura?
- Thrombotic microangiopathy caused by severely reduced activity of vWF cleaving protease ADAMTS13
- Characterized by small vessel platelet rich thrombi that causes thrombocytopenia, microangiopathic hemolytic anemia and widespread multiorgan thrombosis and injury
What are the different types of TTP?
hereditary TTP (<5%): also known as Upshaw schulman syndrome. Inherited mutations isn ADAMTS13
Acquired TTP (>95%): autoimmune or immune mediated TTP. Result of development of autoantibodies inhibitors to ADAMTS13. Categorized further into primary (idiopathic) or secondary cause
What are the secondary causes of TTP?
- Pregnancy (female predominant with median age of 41 years (rare in children)): accounts for 5-25% of all cases of TTP
- Connective tissue diseases: SLE, RA, sjogren syndrome
- Infections: CMV infection, HIV infection
- Drug induced: clopidogrel, ticlopidine, cyclosporine, quinine
What is the pathogenesis of TTP?
- Von willebrand factor (vWF) has multiple ADAMTS13 specific cleavage sites that are susceptible to cleavage by protease when exposed. ADAMTS13 is a metalloprotease that regulates the platelet aggregating activity of vWF by cleaving it at specific sites
- Deficiency of von willebrand factor (vWF) cleaving protease ADAMTS13 in TTP
Deficiency is due to inherited mutations in the enzymes or autoantibodies against it
Results in increased levels of unusually large vWF multimers - Consequences of vWF induced platelet aggregation
Thrombocytopenia due to platelet consumption. Microangiopathic haemolytic anemia from mechanical fragmentation or RBCs.
What is ss of TTP?
Clinical pentad in 5% of patients: fever, fluctuating neurological symptoms, renal impairment, microangiopathic hemolytic anemia (MAHA), thrombocytoepnia
FAT RN = Fever, anaemia (MAHA), thrombocytopenia, renal dysfunction, neurological abnormalities
SS of hemolytic anemia: jaundice, pallor, dyspnea, palpitation, fatigue and wewakness
SS of thrombocytopenia: subcutaneous bleeding (petechiae, purpura, ecchymosis), mucosal bleeding: epistaxis, gum bleeding, menorrhagia), retinal hemorrhage, intracranial hemorrhage
SS of CNS involvement: headache, confusion, focal neurological deficits: weakness, paresthesia, seizure, visual disturbance
SS of CVS involvement (MI, arrhythmia, HF): chest pain, orthopnea, paroxysmal nocturnal dyspnea)
SS of GI involvement (bowel ischemia): nausea and vomiting, abd pain, diarrhea
SS of UG involvement: microscopic or macroscopic haematuria, proteinuria, oliguria/anuria
Ix for TTP?
- CBC: anemia (microangiopathic hemolytic anemia, MAHA), thrombocytopenia (deposition of platelets in microthrombi)
- Peripheral blood smear: schizocytes (fragmentation of RBC as RBC passes through platelet rich microthrombi in the microvasculature. Nucleated RBC: normoblasts. Polychromasia
- Clotting profile: should be normal
- Serum haptoglobin level: decreased haptoglobin (free hb from hemolysis binds to haptoglobin and the complex is rapidly removed by liver)
- Serum LDH: increased LDH (reflects both hemolysis and tissue damage due to systemic ischemia)
- LFT: hyperbilirubinemia (elevated level of unconjugated bilirubin due to haemolysis)
- Urinalysis: dark urine
- Direct and indirect antiglobulin (Coombs) test: immune mediated hemolysis typically negative
- ADAMTS13 and inhibitor tests: severely reduced ADAMTS13 activity <10% during an acute episodes is a hallmark of acquired TTP. presence of antibodies against ADAMTS13
CT scan: typically normal. May show changes consistent with posterior reversible encephalopathy syndrome (PRES)
What is treatment for TTP?
TTP is a medical emergency. Platelet transfusion not indicated due to possible exacerbation of thrombosis
- Plasma exchange
Indicated in patiens with a presumptive dx of TTP
Should be initiated within 4-8 hours of clinical dx
Should not be delayed while awaiting results of ADAMTS13 activity level
Plasma replacement choices: solvent/detergent plasma, fresh frozen plasma.
Plasma infusion is not an adequate substitute for plasma exchange in the initial treatment of TTP but can be used as a temporizing measure if an unavoidable delay in plasma exchange is expected - Corticosteroids
High dose oral prednisolone 1mg/kg/day
IV methylprednisolone 1g/day for 3 days - Rituximab
What are the general features of acute myeloid leukemia?
Well defined hematopoietic neoplasms involving precursor cells committed to myeloid line of cellular development (erythroid, granulocytic, monocytic, megakaryocytic)
Characterized by clonal proliferation of myeloid precursor with a reduced capacity to differentiate into more mature cellular elements
* Accumulation of leukemic blasts or immature forms in the bone marrow, peripheral blood and other tissues
* Decreased production of normal RBC, mature granulocytes (neutrophils) and platelets.
* Increased production of malignant cells
What is the epidemiology of AML?
Most common acute leukemia in adults and accounts for 80% of cases
Acute leukemia is the most common childhood malignancy accounting for 30%
ALL accounts for majority of childhood leukemia accounting for 80%
AML is much less common than ALL accounting for 15% of all leukemia
Disease incidence increases with age. Median age of dx is 65 years.
What are the RF for AML?
Chemical exposure
Radiation exposure
Smoking
Chemotherapy drugs
* Alkylating agents (Cyclophosphamide/ Ifosfamide)
* Topoisomerase II inhibitors Genetic abnormalities
* Down’s syndrome (Trisomy 21) (15 – 20x increase in risk)
* Bloom’s syndrome
* Fanconi anemia
Acquired hematopoietic conditions
* Myelodysplastic syndrome (MDS)
* Myeloproliferative neoplasm (MPN) (particularly CML)
* Aplastic anemia
* Paroxysmal nocturnal hemoglobinuria
What are the SS of haematological abnormalities?
Anemia
* Pallor
* Palpitation
* Tachypnea
* Fatigue
* Decreased exercise tolerance (ET)
Neutropenia
* Fever
* Mucositis
* Recurrent infections Thrombocytopenia
* East bruising
* Petechiae/ Purpura/ Ecchymosis
* Gingival bleeding/ Epistaxis/ Menorrhagia
Constitutional symptoms
* Fever
* Irritability
* Anorexia and weight loss
* Fatigue and malaise
What are the signs of infiltration of haematological malignancy to other areas?
Gingival hypertrophy
* Especially in monocytic subtypes which has predilection to infiltrate gum and skin
Leukemia cutis
* Infiltrative lesions suggestive of extramedullary leukemic involvement
* Subcutaneous nodules and violaceous/gray blue in color
Myeloid sarcoma (chloromas)
* Extramedullary tumor of leuekemic cells (deposits of myeloid blasts outside the bone marrow that cause desrtruction or compression in normal tissues
* Commonly seen in the orbit and epidural space but can occur anywhere –> associated with t821
Hyperleukocytosis and leukostasis
* Presents in 10-20% of patients with newly diagnosed AML
* Leukostasis is symptomatic hyperleukocytosis: WBC occluding the microcirculation leading to symptoms of decreased tissue perfusion typically causing neurological and respiratory distress. Resiratory: dyspnea/hypoxia. CNS: visual blurring/headache/dizziness/ tinnitus/confusion/coma/ TOMA
* Medical emergency with mortality in 1 week reaching 20-40% left untreated. Cytoreduction with induction chemotherapy, hydroxyurea or leukapheresis. Prophylaxis for tumor lysis syndrome with aggressive hydration and hypouricemic agents including allopurinol or rasburicase.
Tumor lysis syndrome
* rapidly proliferating and drug sensitive neoplasm
* Hyperuricemia, hyperK, hyperphosphatemia, hypocalcemia and raised LDH and metabolic acidosis
Disseminated intravascular coagulopathy (DIC)
* especially APL. Platelet transfusion and appropriate coagulation factors such as cryoprecipitate for severe hypofibrinogenemia can be considered in select patients
What is the diagnostic criteria for AML?
Requires both of the following
Evidence of bone marrow infiltration
* >20% blasts of the total cells of the peripheral blood or bone marrow aspirate
* Leukemia with certain genetic abnormalities such as those with t8;21, inv16 or t15;17 and myeloid sarcom are considerd diagnostic of AML without regard to blast count
Leukemic cells must be of myeloid origin
* Presence of Auer rods
* Cytochemistry positivity for myeloperoxidase
* Presence of myeloid markers by immunophenotyping
What Ix for AML and results?
CBC with DC
* Anemia
* Leukocytosis
* Thrombocytopenia
Clotting profile: look for evidence of DIC (PT,aPTT and Ddimer all increased. Decreased fibrinogen)
LFT/RFT and CaPO4 level
* Look for evidence of tumor lysis syndrome: hyperK, hyperP, hypoCa
Serum LDH and uric acid level: signs of TLS
Peripheral blood smear
* Circulating myeloblasts (95% of cases), Auer rods: pathognomonic of myeloblasts
Bone marrow aspirate and trephine biopsy
* Hypercellular bone marrow
* >20% of blasts: pronormoblast, myeloblast, abnormal promyelocyte, promonocyte, megakaryoblast
* Presence of auer rods: pathognomonic of myeloblasts (pink or red like granular structure in cytoplasm)
What are the special investigations for white cell disorders?
- Cytochemistry: MPO reaction (are blasts of myeloid lineage)
- Immunophenotyping (peripheral blood/BM aspirate and trephine biopsy)
Flow cytometry (identification of cell surface antigens)
Myeloid lineage: CD117, CD13, CD33
Monocyte lineage: CD11b, CD64,CD14, CD15 - Cytogenetics (BM trephine biopsy)
Conventional karyotyping with FISH or RT-PCR
Presence of certain cytogenetic abnormalities are sufficient for dx of AML
AML with t(8;21)(q22;q22); RUNX1-RUNX1T1
AML with t(15;17) (q22;q12); PML RARA (APL)
AML with inv(16)(p13.1q22)(p13.1;q22); CBFB-MYH11
What is treatment for AML?
- Chemotherapy
Differences between AML and ALL
AML has shorter duration of treatment due to absence of maintenance phase chemotherapy
Steroids not used in AML, CNS prophylaxis not indicated in AML
Induction (7+3 days): rationale (use of cytotoxic agents to eradicate leukemic cells in bone marrow and in circulation)
Outcomes
Favorable outcome = complete remission (does not = cure): eradication of all detectable leukemic cells (<5% blasts) from bone marrow and blood. Restoration of normal haematopoiesis (>25% cellularity and normal peripheral blood counts)> patients will relapse within 4-8 months unless given additional cytotoxic therapy
Cytarabine + daunorubicin
Cytarabaine (antimetabolite): 7 days of continous infusion
Daunorubicin/idaraubicin (anthracycline): followed by 3 days
Consolidation: must always follow up induction with consolidation regimen. Destroys leukemic cells that survived induction chemotherapy but undetectable by conventional studies
* Cytarabine (high dose)
* Cytarabaine + daunorubicin: standard consolidation for older adults
* Allogenic HSCT: indicated in young adults with unfavorable risk AML. Graft vs tumor effect that decreases relapse rates
- Allogenic haematopoietic stem cell transplantation
always ask for family members such as siblings for potential allogenic HSCT candidates
Indicated in young adults with unfavorable risk of AML or risk of relapse cases after complete remission.
MOA: T cell in donor graft induce a graft vs leukemia effect against residual disease that has survived the conditioning
HLA typing required - Supportive care
TLS prophyalxsi: hydration and allopurinol/rasburicase. Prevention of uric acid nephropathy or renal failure
Antimicrobial prophylaxis
Prolonged bone marrow suppression associated with high incident of infections especially S. viridans sepsis and S.viridans shock syndrome as well as fungal infection such as aspergillus infection. Prophylactic antibiotics or G-CSF for bacterial infections. Prophylactic antifungals (fluconazole/itraconazole) for fungal infections
What is treatment for APL (acute promyelocytic leukemia)?
All transretinoic acid (ATRA) + arsenic trioxide (ATO)
APL characterized by a gene rearrangement involving the retinoic acid receptor: t(15;17);PML RARa in >95% of cases. Very responsive to ATRA and arsenic trioxide is an effective non cytotoxic therapy
Differentiation of APL from other forms of leukemia is important
APL associated with higher risk of DIC and life threatning bleeding especially intracranial bleeding
APL responds well to initial treatment with all transretinoic acid and chemotherapy
APL associated with a good prognosis: best prognosis amongst all AMLs with >90% cure
What is the prognosis of AML?
Complete remission (CR) achieved in
* 70 – 80% in patients < 60 years old
* 40 – 50% in patients > 60 years old
Overall survival is variable depending on prognostic factors
* Poor prognostic factors include age > 60 years old, unfavorable cytogenetics, poor performance status or antecedent MDS/MPN
Prior exposure to
* Radiation
* Chemotherapy
* Toxic chemicals
Past history of
* Chronic myeloid leukemia (CML)
* Myelodysplastic syndrome (MDS)
* Myeloproliferative neoplasm (MPN)
Which type of acute leukemia commonly affects gum and skin?
Acute monocytic leukemia
* A type of AML
* Has a predilection to infiltrate gums and skin
What examinations are usually performed on the bone marrow biopsy for a precise classification of the leukemia?
Morphological examination
Cytochemistry
Immunophenotyping
Cytogenetics
Molecular genetics
Why is it important to differentiate acute promyelocytic leukemia (APL) from other types of acute
myeloid leukemia (AML)?
APL is associated with a higher risk of life-threatening bleeding especially intra-cranial bleeding
* Require intensive transfusion of platelets and fresh frozen plasma
APL responds well to initial treatment with all-trans retinoic acid and chemotherapy
* Responds well to all-trans retinoic acid and arsenate therapy
APL is associated with a good prognosis
What are the common causes of neutropenic infection?
Gram -ve infections (major)
Gram +ve infections
* Become increasingly common
* Often associated with the use of indwelling central venous catheter
Fungal infection
* Prolonged neutropenia is commonly associated with fungal infection
What are the general features of ALL (acute lymphoblastic leukemia (ALL)?
Malignant proliferation of lymphoid cells blocked at an early stage of differentiation
Malignancy of lymphoid cells that has primary involvement of blood and bone marrow
Leukemia (ALL/CLL): primary involvement of blood and bone marrow
Lymphoma: solid tumors of the immune system
ALL when >25% blasts in BM
Lymphoma preferred term when the process is confined to a mass lesion with minimal or no blood and bone marrow involvement (<25% blasts in BM)
What is the epidemiology of ALL?
- Occurs more often in males than females
- Peak incidence =2-5 years
- ChildreN: ALL>AML
- Adults: AML?ALL
Acute leukemia is the most common childhood malignancy accounting for 30%
ALL accounts for majority of childhood leukemia accounting for 80%
AML is less common than ALL accounting for 15% of all leukemia
Childhood ALL is the 1st disseminated cancer shown to be curable
What is the ddx of ALL?
Other malignancy with BM involvement
* Neuroblastoma
* Retinoblastoma
* Rhabdomyosarcoma
* Ewing sarcoma
Differentiation diagnosis of fever and lymphadenopathy
* Infectious mononucleosis
Differentiation diagnosis of fever, bone pain and joint swelling
* Juvenile idiopathic arthritis (JIA)
Differential diagnosis of pancytopenia/ failure of single cell line
* Immune thrombocytopenia (ITP)
* Aplastic anemia
Signs of infiltration of haematopoietic system in ALL?
Infiltration is common
Lymphadenopathy (50%)
* Indicative of extramedullary leukemic spread. LN >1cm in greatest diameter is enlarged except epitrochlear nodes enlarged if >5mm, inguinal nodes >15mm, cervical nodes are >20mm. Lymphadenopathy associated with malignancy is non tender, firm, rubbery and mated which persists or progress despite antibiotic therapy
Hepatomegaly: most common finding in association with childhood leukemia
Splenomegaly: common in childhood leukemia
Bone and joint pain: bone pain particularly in long bone and LL caused by leukemic involvement of periosteum and aseptic osteonecrosis due to malignant cell necrosis in bone marrow.
Bone pain can be severe and awake the patient at night (nocturnal pain). Joint swelling and effusion may be present.
Differentiation of MSK pain in rheumatological disorders (JIA) and malignancy
Morning stiffness and rash occurs more commonly in JIA
Nocturnal pain and non articular bony pain occurs more commonly in leukemia
What are signs of infiltration to other areas in ALL
CNS leukemia (more common in ALL than AML since myeloid cells do not travel as extensive than lymphoid cells): headache, nausea and vomiting, neck stiffness, seizures, CN palsy
Mediastinal mass: classically seen in T cell-ALL. May compress on trachea and leads to respiratory distress and wheezing. May compresson SVC and leads to SVCO which is manifested as dysphagia, dyspnea and swelling of neck, face and UL
Testicular enlargement (testicular leukemia)
Tumor lysis syndrome: HyperK, HyperP, Hyperuricemia, HypoCa. Raised LDH and metabolic acidosis
What are the Ix for ALL?
CBC with DC: anemia, leukocytosis (neutropenia), thrombocytopenia
Clotting profile
LFT/RFT and CaPO4 level: TLS signs
Serum LDH and uric acid level: TLS signs
Peripheral blood smear: circulating lymphoblasts
Bone marrow aspiration and trephine biopsy
* Presence of >25% of lymphoblasts (diagnostic)
* Hypercellular bone marrow: partial or total replacement of normal cellular components of marrow by immature or undifferentiated cells
CSF analysis by lumbar puncture
* Included in initial evaluation –> 5-10% of patients have blasts in the CSF.
* If lymphoblasts are found and CSF leukocyte count is elevated than overt CNS/meningeal leukemia is present (reflects a worse stage and indicates the need for additional CNS and systemic therapy)
What are the special investigations for ALL?
Morphology: absence of granules as seen in myeloid lineage, absence of auer rods
Cytochemistry: terminal deoxynucleotidyl transferase positive in 95% of ALL
Immunophenotyping
* Leukemic cells are classified according to immunophenotyping using an extensive panel of monoclonal antibodies to cell surface “cluster of differentiation”: B precursor lineage (70% in children; 75% in adults) T precursor lineage (15% in children; 25% in adults)
Flow cytometry
B cell: CD10, CD19, CD20, CD22
T cell: CD2, CD3, CD4,CD5, CD7, CD8
* Cytogenetics (BM trephine biopsy)
t922 BCR/ABL1 translocation (Ph chromosome): addition of TKI (imatinib) to intensive CT backbone dramatically improves survival
t (variable;11q23)
t(12;21) ETV6/RUNX1 rearrangeemnt
Hyperdiploidy (54-58 chromosomes): present in 20-25% of childhood ALL: associated with a more favorable prognosis
What is treatment of ALL?
Majority patients achieve remission at the end of induction phase
Minimal residual disease: bone marrow aspiration and assesed by PCR or flow cytometry
Interim bone marrow aspiration to assess disease response to treatment. Higher levels of MRD at the end of induction suggest a poorer prognosis and higher risk of subsequent release
ALL vs AML treatment
ALL has longer duration of treatment, steroid is used in ALL treatment, CNS prophylaxis routinely given to all ALL patients
Induction (4 weeks): use of cytotoxic agents to eradicate leukemic cells in bone marrow and in circulation
Vincristine (weekly) + corticosteroids (daily)+ asparaginase (single dose)
Standard induction CT for t(9;22)/BCR ABL1-ve ALL
TKI (imatinib) + vincristine + corticosteroids + asparaginase indicated for t(922)/BCR ABL1 +ve ALL
Consolidation (4-8 months)
Antimetabolite: cytarabine/methotrexate
Anthracyclines: daunorubicin/doxorubicin
Alkylating agents: cyclophosphamide/ifosfamide
Top inhibiotrs: etoposide/etopophosphamide
Maintenance (2-3 years)
6-mercaptopurine (6-MP) + methotrexate + vincristine + prednisone
- Allogenic haematopoietic stem cell transplantation
Always ask for family members such as siblings for potential allogenic HSCT candidates
Indicated in patients with high risk disease that have an increased incidence of relapse during delayed intensification CT
Patient >10 years of old with severe hypodiploidy, patient >1 year of age with 11q23 rearrangements
HLA typing required - CNS prophylaxis
Prevent leukemic meningitis
Regimen: triple intrathecal chemotherapy (methotrexate/cytarabine/hydrocortisone) - Supportive care
TLS prophyalxsi: hydration +allopurinol/rasburicase
Antimicrobial prophylaxsi: must receive prophylactic treatment for pneumocystic jiroveci (PCP) with cotrimoxazole (septrin)
RBC or platelet transfusion: CT often produces severe myelosuppression requiring transfusion
What is the prognosis of ALL
Cure achieved in 50 – 60% if good prognostic factors but 10 – 30% with poor prognostic factors * Good prognostic factors
o Younger age
o Early attainment of complete remission (CR) without MRD o WBC < 30,000/ μL
o T-cell immunophenotype
o Absence of Ph chromosome or t(4:11)
What is the vaccination protocal for ALL?
- ALL patients should only receive inactive vaccination during chemotherapy
- Live-virus vaccines such as MMR and oral poliovirus are contraindicated
What is general feature of CML?
What is the epidemiology?
MPN characterized by dysregulated production and uncontrolled proliferation of mature and maturing granulocytes with fairly normal differentiation
Occurs more often in males than females
Median age of dx is 50 years
What is pathogenesis of CML?
BCR ABL1 fusion gene
ABL1 gene on ch9 to BCR gene on ch22
BCR-ABL1 protein (tyrosine kinase) is no longer under control by cellular mechanism and causes cell to divide uncontrollably
What is the triphasic disease phase of CML?
What are signs of infiltration of haematopoietics system in CML?
Splenomegaly (48-76%): can be massive extending to the right iliac fossa depending on when it is dx. Inability to get above the mass and it moves up and down with respiration. Dull on percussion and presence of a notch. Auscultation over massive spleen may reveal a splenic rub.
What Ix for CML and results?
CBC with DC
* Normal/anemia
* Leukocytosis >25,000uL (often >100,000uL): virtually all cells of neutrophilic series (myeloblast/promyelocyte/myelocyte/metamyelocyte/band cells/neutrophils) with peaks in myelocytes and segmented neutrophils. Presence of greater percentage of myelocytes than metamyelocytes are known as myelocyte bulge which is a classical CCML finding
Other WBC DC
* Absolute basophilia is seen in all cases
* Absolute eosinophilia is seen in 90% of cases
* Absolute monocytosis is not uncommon as well
* Normal/thrombocytosis/thrombocytopenia: thrombocytopenia only in blastic crisis when progress into acute leukemai and should alarm reconsideration of other diagnostic possibilities than CML
Peripheral blood film
* Thrombocytosis
* Leukocytosis: virtually all cells of neutrophilic series and basophilia
* Presence of blasts: chronic phase <10%, accelerated phase: 10-19%, blastic phase >20%
Bone marrow aspiration and trephine biopsy
* Hyperplasia of granulocytic series
* Increase in reticular fibers and vascularity
Special Ix
Cytogenetics (BM trephine biopsy)
Conventional karyotyping: detection of Ph chromosome (small chromosome 22)
FISH: test for BCR-ABL1 fusion gene, actual visualization of t(9;22)by FISH. Overlapping of chromosome 9 and 22 (red and green = yellow)
RT-PCR: BCR-ABL1 fusion gene
What is treatment for CML?
TKI: curative –> 1st gen: imatinib, 2nd gen: nilotinib/dasatinib/bosutinib
Hydroxyurea: only for symptomatic treatment –> not curative
Allogenic HSC transplantation: curative treatment option but at the cost of increased potential toxicity and early mortality. Indicated for young patients not responding to TKI treatment and has a suitable donor
How to monitor the prognosis for CML?
Molecular genetics (PCR): most sensitive due to amplification. Measurement of fusion RNA level but not fusion gene or fusion protein. Detect and quantify BCR-ABL1 fusion transcripts by mRNA. mRNA is used instead of DNA because all the introns are spliced and investigator does not have to account for the variability of intron breakage in BCR and ABL1 gene when designing primer.
* qRT-PCR
* Expression of MRD level = BCR-ABL1/ABL1
Pitfalls of qRT-PCR for MRD (minimal residual disease) monitoring: unable to detect fusion transcript even if CML is present
Name of this genetic test
What phase of the mitotic cycle does this cell belong to
From results shown, what conclusion can you draw concerning the dx of this patient
Why is there discrepancy between the findings of the 2 genetic tests in this patient
FISH
Interphase: easier to perform since the leukemic cells need not be altered
CML due to fusion gene signl
In normal cells there should 2 BCR (green) and 2ABL1 (red) genes. Spatial location of the 4 signals should be random as they are located on separate chromosomes.
In cells of CML patient a fusion signal is detected as a pair of probe will go together
Conventional cytogenetic study: detect normal karyotype which indicates that the presence of BCRABL1 fusion gene in FISH is not due to balanced translocation
FISH: fusion gene is caused by insertion instead of translocation. A small fragmetn of ABL1 gene breaks from chromosome 9 and is inserted into BCR gene in chromosome 22 to create a fusion gene. Such breakage is sub-microscopic and hence is not detected by conventional cytogenetic study.
What are the adv and disadv of conventional cytogenetics vs FISH in detecting leukemia?
What are the general features of CLL?
Epidemiology?
Progressive accumulation of functionally incompetent lymphocytes which are monoclonal in origin
Occurs more often in males than femaels
Median age of dx is 70 years, never in childhood
What are the signs of infiltration to haematopoietic system and other areas in CLL?
Lymphadenopathy (50-90%): generalized or localized. The more generalized the more likely the dx is CLL. Commonly involved LN include cervical, supraclavicular and axillary LN. Enlarged LN are non tener, firm, rounded, discrete and freely mobile on palpation
Hepatomegaly (15-25%)
Splenomegaly (25-55%)
Dermatological system
* Leukemia cutis: most commonly involves the face. Nodular and violaceous/gray blue in color.
* Can also manifest as macules, papules, nodules, ulcers or blister
What is the diagnostic criteria for CLL?
Requires both of the following
* Absolute B lymphocyte count in periphreal blood >5x 10^9/L with a preponderant population of morphologically mature appearing small lymphocytes
* Evidence of clonality of circulating B lymphocytes by flow cytometry of peripheral blood with majority of population expressing the following pattern of monoclonal B cell markers
Expression of B cell associated antigens (CD19, CD20,CD23)
Expression of T cell assocateid antigens (CD5)
What Ix for CLL?
CBC with DC
* Anemia: pure red cell aplasia, AIHA
* Leukocytosis (major is a diagnostic feature in elderlty)
* Thrombocytopenia: autoimmune thrombocytopenia
Peripheral blood smear: lymphocytosis (leukemic cells are small, mature appearing lymphocytes with dense nucleus, partially aggregated chromatin and without discernible nucleoli
Bone marrow aspiration or trephine biopsy
* Not requires for dx of CLL. Presence of lymphocytes for >30% of all nucleated cells
LN biopsy
* Diffusely effaced nodal architecture with occasional residual naked germinal centers
* Infiltrate composed of mature appearing, small lymphocytes with a mixture of prolymphocytes and paraimmunoblasts
Serum immunoglobulin level
* Hypogammaglobulinemia
* Decreased IgG, IgA and IgM
Special test: immunophenotyping
Flow cytometry
B cells: CD10, CD19, CD20, CD22, CD23
T cell: CD2,CD3, CD4, CD5, XD7
What is treatment for CLL?
General approach: always do chemotherapy (says Kwong sir)
Purine analogues: fludrabine/pentostatin
Alkylating agents; cyclophosphamide/bendamustine/chlorambucil
Monoclonal antibodies: rituximab/ofatumumab/obinutuzumab
TKI: ibrutinib
HSCT: indicated in young patietns with aggressive disease
What are the general features of lymphoma?
What is the classification?
Lymphoma are clonal malignancies of lymphoid system
Most common site of primary extranodal system is GIT (stomach, duodenum = submucosal) followed by skin. Other rare sites include bone, kidney, bladder, prostate, testis, breast, ovary, orbit, heart
Pathological classification by WHO
Histological appearance
Immunophenotyping (flow cytometry): B cells (85%), T cells (10-15%), NK cells (5%)
Cytogenetics/molecular genetics
All 3 features are needed for appropriate classifcation of lymphoma
What is hodgkins lymphoma features and non classical HL (nodular lymphocytic predominant Hodgkin lymphoma)?
Hodgkin lymphoma: presence of Reed Sternberg cells
RS cells are clonal B cells (ALL HL are B cell lymphoma), bilobed nucleus + prominent nucleoli with surrounding clear space
Arises from gernal center or post germinal center
Bimodal distribution (15-35 years and >50 years old)< less common than non Hodgkinsl ymphoma
Mode of spread
* Affects superficial (usually cervical or supraclavicular) +/-mediastinal LN
* Nodal disease with a tendency to spread in an orderly anatomical fashion to contiguous areas of LN
What are the features of non Hodgkins lymphoma?
- Absence of Reed sternberg cells
- Consists of a diverse group of malignancy neoplasms derived from precurosr B or T cell, mature B or T cells or NK cells: majority of NHL is still B cells in origin (85%)
- Associated conditions
Infectious (H.pylori, EBV, HTLV-1)
Autoimmune disorders (SLE/RA/Sjogren syndrome)
Immunodeficeincy (HIV/post transplant recipients)
Median age of dx is 65 years old
Mode of spread
* Diffuse nodal and/or extranodal spread
* Tendency to spread haematogenously with non contigous lymphatic spread unlike in Hodgkins lymphom
* More common to have CNS involvement
WHO classification of lymphoid malignancy for B cell?
WHO classification of lymphoid malignancy for T cell/NK cell?
What are the specific features of B cell lymphoma?
What are the specific features of T cell lymphoma?
What are the specific features of NK cell lymphoma?
What are the conditions associated with development of lymphoma?
Bacterial infection: H.pylori (gastric MALT lymphoma)
Viral infection
* EBV: burkitt lymphoma, NK cell lymphoma (nasal)
* HIV: primary lymphoma and primary CNS lymphoma are AID defining malignancies
* Human T cell lymphotropic virus (HTLV-1): adult T cell leukemia/lymphoma
* Hep C virus: MALT lymphoma
Autoimmune disorders
* Hashimotos thyroditis
* Sjogren syndrome
* SLE
* RA
* Autoimmune hemolytic anemia
Immunodeficiency state
* Inherited immunodeficiency state
* Acquired immunodeficiency state: HIV infection, solid organ or HSCT, immunosuppressants
Inflammatory GI diseases: IBD, GI nodular lymphoid hyperplasia
What are the primary and secondary lymphoid organs?
What classification used to stage lymphoma?
What is the clinical course of aggressive vs indolent lymphoma?
Aggressive lymphoma
* Presents acute or subacutely with rapidly growing mass, systemic B symptoms, elevated serum LDH and uric acid
* Goal of management = cure since it has a higher chance of cure
Indolent lymphoma
* Presents insidiously with slow growing lymphadenopathy, hepatomegaly, splenomegaly or cytopenia
* Goal of management: symptomatic relief since it is typically incurable
What are systemic symptoms of lymphoma?
B symptosm (fever+ weight loss +night sweats)
Components of B symptoms: fever of unknown region >38C, unexplained weight loss >10% over past 6 months, drenching night sweats
Hodgkins lymphoma: Pel Ebstein fever (cyclic fever recurring at variable intervals of days or weeks and lasts for 1-2 weeks before waning), pruritis
Non Hodgkins lymphoma: B symptoms may vary between subtypes of NHL
Painless lymphadenopathy
* Hodgkin lymphoma presents with superficial (usually cervical or supraclavicular)+mediastinal lymphadenopathy
* Non Hodgkin lymphoma presents with peripheral lymphadenopathy
* Discrete, painless, firm or rubbery
* Persists and does not subside over weeks
What to do for PE of lymphoma?
General exam: skin involvement
Lymphoid survey
Waldeyers ring: adenoid –> tubal –> palatine –> tonsils
* Standard lymph node
o Firm or rubbery lymph nodes
oCervical –> Supraclavicular–> Axillary –> Epitrochlear –> Inguinal –>Femoral
Popliteal lymph node
* Abdominal lymph node
o Mesenteric lymph node/ Retroperitoneal lymph node
* Liver and spleen
Head and neck examination
* Nodal and extranodal involvement of H&N is suggested by enlargement of preauricular
lymph nodes and tonsillar asymmetry
* Primary CNS lymphoma commonly involves the eyes
Chest examination
* Mediastinal adenopathy may be detected on clinical examination or chest radiograph
* Presents with persistent cough, chest discomfit with an abnormal CXR
Abdominal examination
Hepatosplenomegaly is common in indolent lymphoma with intact LFT
What are the Ix for lymphoma?
- CBC with DC
- Peripheral blood smear
- LFT
- RFT (nephrotoxic CT drugs)
- Serum Ca2+ and PO4-: hyperCa due to PTHrP (paraneoplastic syndrome), evaluation of tumor lysis syndrome
- Serum LDH level: rapidly growing tumors of NHL such as Burkitt lymphoma
- Serum uric acid level
- Serum b2-microglobulin level: used in follicular lymphoma and other indolent lymphoma for prognostic purpose
- Serum protein electrophoresis. Detection of monoclonal immunoglobulin (M spike). Large M spike associated with lymphoplasmacytic lymphoma. Small M spike associated with small lymphocytic lymphoma/chronic lymphocytic leukemia and extranodal marginal zone lymphoma
- HIV serology: systemic non HL and CNS lymphoma are AIDS defining malignancy
- HBV and HCV serology: must include HBsAg, anti HBs and anti HBc +-HBV DNA viral load
- EBV serology: EBV VCA IgA and EBV EA IgA, EBV DNA viral load
- Serum autoantibodies
- Evaluation of other tissues: pleural fluid analysis by thoracentesis, peritoneal fluid analysis by paracentesis. CSF fluid by lumbar puncture (indicated in primary CNS lymphoma, lymphomatous meningitis or patients with Burkitt lymphoma which has a high incidence of CNS involvement
Radiological tests
PET CT scna: staging disease.
All nodular lymphoma histology is considered FDG avid except chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma with Waldenstrom macroglobulinemia and marginal zone lymphoma
Excisional LN biopsy (sufficient tissue for histologic, immunologic, molecular biologic assessment and classification)
LN >1cm diameter should be biopsied
LN>2cm has the best diagnostic yield
Site of LN: enlarged peripheral LN are generally preferred
FNA only for initial screening for peripheral lymphadenopathy to detect benign form of reactive lymphadenopathy (viral/bacterial, non inflammatory)
Bone marrow aspirate/trephine biopsy: done prior to initation of treatment as part of the staging evaluation. Typically evaluated for morphology, immunophenotyping, cytogenetics and molecular genetics.
Histological exam: pattern of LN involvement (nodular/follicular/diffuse pattern)
Immunophenotyping
* Flow cytometry: on fresh unfixed single cell suspensions. Detection of surface immunogloblin light chains which is very helpful in determining clonality of B cell proliferation. Superior to IHC as able to etect 2 or more markers simultaneosly, rapid turnaround time, greater quantitative capacity and higher sensitivity for certain markers
* Immunohistochemistry: on sections of fixed or fresh frozen tissues. Expression of cell surface lymphoid differentiation antigens are used to distinguish B cell and T cells at various developmental stages
Cytogenetics: karyotyping and FISH
Molecular genetics: IgH gene rearrangement by PCR, T cell receptor gene rearrangement by PCR
What is pre treatment functional testing for lymphoma?
- Cardiac functioning: screening with echocadiogram. Baseline evaluation of cardiac function such as ejection fraction considered if patients likely to be treated with anthracycline (doxorubicin) or mediastinal irradiation
- Pulmonary function: CXR/CT thorax, DLCO as pulmonary function considered when patient likely to be treated with bleomycin
- HBV/HCV screeing: antiviral prophyalxis required before starting on rituximab
What is the treatment regimen for Hodgkin lymphoma?
What is the treamtent regimen non-Hodgkin lymphoma?
What are the complications of lymphoma?
- Oncological emergency of NHL
CVS: SVCO/ IVCO/ Venous thromboembolic disease/ Pericardial tamponade
Gastrointestinal: Intestinal obstruction/ Hepatic dysfunction
CNS: Spinal cord compression/ Lymphomatous meningitis
Urogenital: Ureteral obstruction/ Hydronephrosis
Respiratory: Acute airway obstruction (mediastinal lymphoma)
Hematology: Hyperleukocytosis (B or T-cell lymphoblastic leukemia/lymphoma)/
Hyperviscosity syndrome (Lymphoplasmacytic lymphoma with Waldenstrom
macroglobulinemia)/ Autoimmune hemolytic anemia/ Leukopenia/ Thrombocytopenia
Endocrine: Hypercalcemia/ Hyperuricemia
Tumor lysis syndrome
Haematological malignancy is highly chemosensitive, high tumor cell proliferation rate. Large tumor burden: bulky disease >10cm in diameter/WBC>50,000uL >2x ULN/organ infiltration or bone marrow involvement
Electrolytes
Hyperuricemia, hyperP, hypoCa, acute kidney injury
Treatment: rasburicase (recombinant urate oxidase) which converts uric acid to solube allantoin
Correction of electrolyte abnormalities (especially hyperK), consideration of renal replacement therapy
Prevention: IV hydration, hypouricemiac agents. Uric acid lowering agents = allopurinol/febuxostat, recombinant urate oxidase = rasburicase
How to make prognosis of hodgkins lymphoma?
How to make prognosis of non hodgkins lymphoma?
What are causes of SVCO?
Malignant causes
* Lung cancer
Venous obstruction results from extrinsic compression of SVC by either the tumor or enlarged mediastinal LN
SCLC: SVCO more common in SCLC accounting for 10% of cases at preentation
NSCLC (most common): but overall NSCLC is the most common malignant cause of SVCO because of higher incidence
* Lymphoma
NHL: diffuse large (DLBCL) and lymphoblastic leukemia are the most common subtypes. SVCO common in patietns with primary mediastinal DLBCL which typically presents with a rapidly enlarging anterior mediastinal mass
Hodgkin lymphoma: rarely a cause of SVCO
* Others: lymphoma, mesothelioma, primary mediastinal germ cell neopplasm, metastasis to mediastinal LNs (breast cancer)
Non malignant causes
* Indwelling intravascular devices: SVCO due to thrombosis from devices such as central venous catheter, cardiac pacemaker leads and implantable defibrillator presidposes to SVCO
* Fibrosing mediastinitis: excessive host response to prior infection with histoplasma and filariasis
* Post radiation fibrosis: patients who recieved prior thoracic RT has increased risk of post radiation local vascular fibrosis
What is the pathophysiology of SVCO?
Obstruction of SVC has 2 mechanisms
* Intrinsic obstruction due to thrombosis of blood within SVC
* External compression or invasion by adjacent pathological processes invovling right lung, LNs and other mediastinal structures
Development of venous collaterals
* Collateral veins may arise from the azygous, internal mammary, lateral thoracic, paraspinous and esophageal venous systems
* CVP remains elevated even when well developed venous collaterals are present
Onset of SS depends on rate of SVCO in relation to recruiment of venous collaterals
* Patients with malignant SVCO develops within weeks to months since rapid tumor growth and can develop collateral flow
* Patients with fibrosing mediastinitis such as due to infection like histoplasmosis may not become symptomatic for years
Consequences of SVCO
* Edema may narrow the lumen of nasal passages and larynx which can lead to dyspnea, stridor, cough, hoarseness and dysphagia
* Edema may lead to cerebral edema and subsequently cerebral ischemia and herniation
What are the SS of SVCO?
Dyspnea (most common)
Cough
Cyanosis
Stridor/ Wheezing
Dysphagia
Chest pain
Swelling of face, neck and upper extremities
Distension of neck veins and chest veins
SS of cerebral edema (may need emergency stenting)
Headache Dizziness Syncope Confusion
What Ix for SVCO?
- CXR: mediastinal widening and pleural effusion
- Duplex USG: cannot directly image the SVC due to acoustic shadowing of overlying ribs. Useful for excluding thrombus in subclavian, axillary and brachiocephalic veins and is the initial imaging for patients with indwelling devices.
- Contrast enhanced chest CT is the most diagnostic modality: level and extent of venous blockage, identify and map venous collaterals and permits identification of underlying venous obstructin
- Digital subtraction venography: gold standard in dx of SVCO and assess extent of thrombus formation
- Biopsy for histopathology
Less invasive approach: sputum cytology, superficial/supraclavicular LN biopsy, thoracentesis, transthoracic needle aspiration biopsy under fluoroscopic/CT/USG guidance
More invasive approach: bronchoscopy, medinastinoscopy, thoracoscopy, thoracotomy/sternotomy
What is the treatment principle for SVCO?
General mangement: prop up for head elevation, O2 supplement
Principle = treatment tailored to specific neoplasm and therefore tissue dx is essential prior to empirical treatment
Emphasis on accurate histological dx before starting therapy. Only use stent in last line for rapid relief that can be achieved using RT
Medical treatment
* Corticosteroids IV dexamethasone 4mg q6h (steroid responsive malignancy including lymphoma and thymoma) patients undergoing RT particularly if laryngeal edema present
* Diuretics: frusemide
* Anticoagulants only when SVC thrombus is present
LMWH preferred over warfarin in malignancy related thrombosis and CrCL>30ml/min. Lower rate of recurrent thromboembolism, less drug interactions with subsequent systemic cancer treatment
Surgical and other treatment
RT: Symptomatic obstruction is a prolonged process (development of collaterals) and therefore should do diagnostic workup prior to RT (as RT sensitive tumors can be shrunk –> will need to wait for increase in size to confirm dx) except severely symptomatic (Stridor/ increased ICP)
Endovascular stenting. Only indicated in patients with severe symptoms who require urgent intervention before tissue dx is avaialble. Recurrent or chronic SVCO following conventional treatment. Stent complications include bleeding, infection, perforation, or rupture of SVC, pulmonary embolism, stent migration and stent failure with reocclusion. Post stenting short term dual antiplatelets (DAPT) for 3 months recommended.
Describe what MPNs are?
Results from clonal expansion involving pluripotent haematopoietic stem cell (HSC)
Production of mature cell which may be normal looking but functionally abnormal
Different from MDS in that cells are not dysplastic. Dysplastic cells mean abnormal proliferation of cells which do not mature.
Proliferation of all 3 haematopoietic lineages although usually clinically manifests abnormality in 1 lineage only
Erythroid lineage, myeloid lineage, megakaryocytic lineage
What is the classification of MPN by WHO?
What mutations are used as clonal markers and diagnostic tools?
Classificaiton
* Polycythemia vera (PV)
* Essential thrombocytosis (ET)
* Primary myelofibrosis (PMF)
* Chronic myeloid leukemia (CM), BCR-ABL1+
* Chronic neutrophilic leukemia (CNL)
* Chronic eosinophilic leukemia, not otherwise specified (NOS)
* Myeloproliferative neoplasm, unclassifiable
Mutation of MPN as clonal markers and diagnostic tools
- JAK2 V617F (Janus kinase): PV = 95%; ET = 50%; PMF = 50%
o Gain-of-function mutation in either exon 14 or exon 12 - CALR exon 9 (Calreticulin): ET = 25%; PMF = 35%
o Occurs in MPNs without JAK2 or MPL mutations - BCR-ABL1 fusion: ALL cases of CML
- MPL/ TET2/ ASXL1: Mutations with lower frequency
- CSF3R: CNL = 60%
Risk of leukemic transformation in AML
Risk of development into myelofibrosis
What are features of polycythemia vera?
Chronic MPN which is distinguished from other MPNs by the presence of an elevated RBC mass (erythrocytosis)
Increased RBC mass insufficient to establish dx as it is observed in other conditions such as chronic hypoxia and EPO secreting tumors
Most frequently caused by GOF mutation in JAK2 V617F in 95% of PV
Presents with erythrocytosis often accompanied by leukocytosis and thrombocytosis
Associated with increased risk of thromboembolic events and risk of progression into AML and myelofibrosis
What are genetics of polycythemia vera
What are secondary causes of erythrocytosis?
JAK2 V617F mutation in exon 14 of JAK2 gene
Mutation in exon 12 of JAK2 gene in 4% of patients
Secondary causes
EPO secreting tumors (most common): RCC, HCC, cerebellar haemangioblastoma, phaeochromocytoma, uterine fibroids
Chronic hypoxemia: chronic pulmonary disease, right to left cardiac shunts, red cell defects (methemoglobinemia, carboxyhaemoglobinemia (CO poisoning)
What are SS of polycythemia vera?
Symptoms
* Pruritis: exacerbated by hot bath (aquagenic pruritis)
* Vasomortor symptoms: headache, dizziness, light headedness, tinnitis, visual blurring, atypical chest pain. Erythromelalgia (painful burning sensation in extremities accompanied by erythema –> associated with acral paresthesia. Pathognomonic of microvascular thrombotic complications with microvascular ischemia which occurs in both PV and ET0
* Symptoms of thrombosis (hyperviscosity): transient ocular blindness, ocular migraine
* Symptoms of bleeding: easy bruising, epistaxis/gum bleeding
Signs of PV
* Facial plethora
* Scratch marks
* Hypertension
* Hepatomegaly
* Splenomegaly
* Engorged retinal vein
Constitutional symptoms: fever, night sweats, fatigue, weight loss, bone pain
What is the diagnostic criteria for polycythemia vera?
What Ix done for polycythemia vera (PV) and results?
What is the treatment plan for polycythemia vera?
Risk stratification
Low risk = age <60 years and no prior thrombosis –> low dose aspirin + phlebotomy to maintain haematocrit <45%
High risk = age >60 years old or prior thrombosis –> low dose aspirin + phlebotomy to maintain haematocrit <45% + cytoreductive therapy with hydroxyurea/pegylated IFNa-ruxolitinib
Medical treatment
Low dose aspirin
* Recommended for all patients with PV unless contraindicated to preven thrombosis
* Patients with platelet count >1000 x 10^9L should be screened for acquired von Willebrand disease by measuring vWF: ristocetin cofactor activity. Aspirin contraindicated in patients with acquired vWD
Hydroxyurea: 1st line cytoreductive agent due to its efficacy, ease of administration, lower cost, long term safety profile and favorable toxicity profile
Alternative cytoreductive agents. Pegylated IFNa = associated with high haematological response with limited toxicity (1st line in young patients who may become pregnant)
Ruxolinib: JAK1/2 inhibitor indicated for patients who are refractory or intolerabel to hydroxyurea
Surgical treatment
Phlebotomy (venosection): recommended for all patients with PV to maintain haematocrit <45%
Controls polycythemia by producing a state of absolute iron deficiency and hence iron supplementation should not be given
Standard one unit of phlebotomy (500ml) should reduce haematocrit by 3% in normal size adult
Prognosis of PV
Conditions associatedw ith PV
Median survival with treatment = 13.5 years
Associated conditions
* Gouty arthritis: increased uric acid due to increased cellular turnover
* Peptic ulcer disease (PUD): increased histamine release from basophila
* Thrombosis: MI/stroke, peripheral vascular disease/ limb ischemia. Superficial thrombophlebitis/DVT/ PE. Portal/splenic/ mesenteric vein thrombosis. Budd Chiari syndrome
What are the features of essential thrombocytosis?
Chronic MPN characterized by excessive clonal platelet production with vasomotor symptoms and a tendency for thrombosis and hemorrhage
Mutations associated with ET that have dx and prognostic implications
* JAK2 V617F
* CALR exon 9
* MPL
* 10-15% of patients have negative for all 3 mutations (triple negative patients)
Associatedw ith increased risk of thromboembolic events sand risk of progression into AML and myelofibrosis
What is the genetics of essential thrombocytosis and physiology?
Normal production of platelets
* Thrombopoietin (TPO) binds to MPL (c-Mpl) receptors on megakaryocytes
* Induces activation of JAK2 and activating STAT5 signaling pathways
* Results in increased megakaryocyte development and thrombopoiesis
Mutations associated with ET that have diagnostic and prognostic implications
* JAK2 V617F: mutation causes unregulated JAK-STAT signal transduction leading to unregulated myeloproliferation causing megakaryocyte hyperplasia
* CALR exon 9 = 25%
* MPL mutation = 3-5%
* 10-15% of patients are negative for all 3 mutations (triple negative patients)
What is the ddx of thrombocytosis (in essential thrombocytosis)
What is the WHO diagnostic criteria for essential thrombocytosis (ET)?
What Ix done for essential thrombocytosis (ET)?
What is treatment for essential thrombocytosis?
What is prognosis of ET
Complications associated with ET?
What are the features of primary myelofibrosis?
Dysregulated myeloproliferation = Atypical megakaryocytic hyperplasia and proliferaetion
Bone marrow fibrosis = Reactive deposition of fibrous connective tissue (reticulin orcollagen) in the bone marrow often with osteosclerosis
o Hallmark of PMF which contributes to ineffective hematopoiesis producing anemia
Leukoerythroblastosis = Peripheral blood demonstrates a triad of teardrop-shaped red cells + nucleated red blood cells + early myeloid forms in later fibrotic stages
Extramedullary hematopoiesis = Results in hepatomegaly and splenomegaly
o Non-functional hematopoiesis with NO significant production of blood cells
What are the genetics of PMF (primary myelofibrosis)?
- JAK2 V617F (Janus kinase) = 45 – 50%
- CALR exon 9 (Calreticulin) = 45 – 50%
- MPL (Myeloproliferation leukemia virus oncogene) mutation = 7 – 10%
- 1 – 2% of patients are negative for all 3 mutations (triple-negative patients)
What are other causes of myelofibrosis?
What are SS of PMF?
What is the diagnostic criteria for pre-PMF?
What is the diagnostic criteria for overt-PMF?
What Ix for PMF?
CBC with DC
* ANemia
* Leukopenia/leukocytosis
* Thrombocytoepnia/thrombocytosis
Peripheral blood smear
* Leukoerythroblastic picture: tear drop shaped red cells (dacrocytes): indicates membrane damage from passage through the spleen
* Nucleated red blood cells: indicates extramedullary haematopoiesis
* Presence of early myeloid forms including myelocytes, promyelocytes and myeloblasts: indicates extramedullary haematopoiesis
Anisopoikilocytosis: anisocytosis = variation in RBC size, poikilocytosis= variatio in RBC shape
Abnormally large platelets with altered granulation and fragment megakaryocytes
Serum LDH level: increased LDH due to ineffective haematopoiesis
Serum uric acid level: hyperuricemia due to increased turnover of haematopoietic tissues –> predispose to gouty arthritis and uric acid stones
Bone marrow aspiration: difficult to aspirate yielding a dry tap and is not diagnostic even if successful.
Bone marrow biopsy: presence of severe extensive reticulin or collagen fibrosis. Reticulin visualized with silver stain, collagen visualized with trichrome stain
Decreased erythropoiesis, increased granulocyte proliferation, increased megakaryocytic proliferation and typia
Genetic testing
JAK2V617F=45-50%, CALR exon9 =45-50%, MPL mutation = 7-10%
1-2% of patients are negative for all 3 mutations
What is treatment for PMF?
What are the general features of MDS?
Heterogenous group of clonal disrorders characterized by ineffective haematopoiesis leading to peripheral blood cytopenia and increased risk of transformation to AML
Haematological condition characterized by
* Increased suspectibility to apoptosis of clonal myeloid progenitors in bone marrow leading to ineffective haematopoisis
* Abnormal cells are not released into circulation (pancytopenia): leads to cytopenia despite generally hypercellular bone marrow
Risk of leukemic transformation: progression to AML may result from clonal progenitors shifting from apoptosis to proliferation.
What is the classification of MDS?
What are the causes of MDS?
What is the ddx for pancytopenia?
What are the SS for MDS?
What are the Ix for MDS and results?
What is the treatment for MDS and prognosis?
What are the general features of aplastic anemia?
AA refers to pancytopenia in association with bone marrow hypoplasia or aplasia without dysplasia, bone marrow infiltrate or bone marrow fibrosis
AA may coexist with or evolve into another haematological disorders
Paroxsymal nocturnal haemoglobinuria: close relationship between PNH and AA
Clonal disorder with acquried somatic mutation of PIG-A gene. Leads to deficiency of GPI anchor for proteins (CD55 and CD59) on the surface of RBCs which normally acts as inhibitors of complement.
Presents with haemolytic anemia due to intravascular hemolysis, pancytopenia if overlap with AA or MDS, smooth muscles dystonia and hypercoagulability
MDS
AML
Epidemiology of MDS?
Bimodal distribution: occurs most commonly in children and young adults aged 10-25 years and adults aged >60 years
What are the causes of aplastic anemia?
Inherited aplastic anemia (15-20%)
Fanconi anemia
* Most common inherited form of AA
* Features: pancytopenia, short stature, microcephaly, absent or hypoplastic thumbs/polydactyly/clinodactyly, gonadal/genital malformations (hypospadias/cryptochordism), developmental delay, VACTREAL-H malformations
* Predisposition to malignancy including MDS, AML and SCC of H&N
* Diagnostic test: NGS to identify mutations. Chromosomal breakage test with diepoxybutane (DEB) or mitomycin (MMC): hallmark fo FA is defective DNA repair. Addition of DEB leads to chromosomal breakage: normal patient can repair but FA patient cannot
Shwachmann Diamond syndrome
* Presents in infancy with bone marrow failure, exocrine pancreatic dysfunction and skeletal abnormalities
* Dyskeratosis congenita: associated with characteristic skin and nail findings
Dyskeratosis cogenita
* Associated with characteristic skiin and nail findings (tongue leukoplakia/nail dystrophy/reticular skin pigmentation)
Telomere abnormalities
* TERT or TERC mutations
Acquired aplastic anemia
Idiopathic (70-80%)
Viral infections
* HIV, Hep virus, herpes viridae (VZV,EBV, CMV, HHV-6)< parvovirus B19 (typically causes pure red cell aplasia and isolated anemia)
Drug induced: extent and timing of bone marrow suppression to CT and other cytotoxic drugs is generally predictable and not considered AA
Drugs assoicated with AA. antibioptics: sulphonamides, anticonvulsants: valproate/ carbamazepine/phenytoin, antithyroid: methimazole/propylthiouracil, NSAID: indomethacin, others: gold
Toxins: chemicals, insecticides
Ionizing radiation
Miscallaneous causes: pregnancy, thymoma, autoimmune disease (SLE, graves), GVHD, post HSCT transplantation
What Ix done for aplastic anemia and results?
What main 2 treatment approaches for aplastic anemia?
Age affected by MM
What are pathological features of multiple myeloma
MM >60 yo
What are SS of multiple myeloma?
Anemia: normocytic normochromic. Causes: bone marrow replacement, kidney damage. Associated symptoms: pallor, fatigue, SOB, tachcyardia, palpitations
Bone pain: production of osteoclast activating factors by myeloma cells or marrow stoma: receptor activator of NFkB ligand
Site: more often in back anad chest, less often in upper and lower extremities
Character: induced by movement
Associated symptoms: decreased height due to vertebral fracture
Renal disease: increased serum creatinine
causes: hypercalcemica (amjor), light chain myeloma cast nephropathy (major), light chain amyloidosis, light chain deposition disease
Hypercalcemia
Fatigue
Weight loss
Others: paresthesia, hepatomegaly, splenomegaly, lymphadenopathy
Associated conditions
* Infections caused by immune dysfunctions: impaired lymphocyte function, impaired normal plasma cell function
* Neurological diseases
Radiculopathy: most common neurological complication of MM, usually in thoracic or lumbosacral regions. Caused by compression of nerve by paravertebral plasmacytoma or collapsed bone
Cord compression: spinal cord compression from extramedullary plasmacytoma or bone fragment of a fractured vertebral body. Suspected with back pain, weakness or paresthesia of LL, bladder or bowel dysfunction
What is the diagnostic criteria for multiple myeloma?
What is the ddx for multiple myeloma?
What is monoclonal gammopathy of undermined significance (MGUS)?
What is smoldering multiple myeloma criteria?
What is Waldenstrom macroglobulinemia (WM) criteria?
What is solitary plasmacytoma criteria?
- Plasmacytoma are tumour composed of plasma cells of variable maturity which are
histologically identical to those seen in multiple myeloma
o May occur solely in bone and outside in soft tissues (extramedullary plasmacytoma)
how to make dx of amyloid light chain amyloidosis (AL amyloidosis)
- Plasma cell proliferative disorders associated with overproduction of monoclonal light chains
- Diagnosis is established by demonstrating amyloid on biopsy of affected tissue such as abdominal fat, bone marrow, rectum or kidney
What Ix for multiple myeloma?
CBC with DC
ESR/CRP
Electrolyte profile: hyperCa
Serum protien level: hyperproteinemia
LFT: normal ALP (meaning osteoblastic acitivity is not increased)
RFT and urinanalysis: increased serum creatinine, proteinuria (myeloma cast nephropathy), light chain amyloidosis (usually urinary protien +ve since most of the proteinuria is comprised of albumin (nephrotic syndrome)
Peripheral blood smear: rouleaux formation (RBC stack of coins), monoclonal plasma cells (rarely seen in MM), leukopenia (20%): suppressed haematopoiesis, thrombocytopeni (5%): M protein interacts with thrombocytes
Bone marrow exam (aspiration and trephine biopsy)
* Plasma cell infiltration >10%
* Normal mature plasma cells
* Myeloam cells: multiple pale bluish white, grape like accumulatin
* Immunopheotyping: normal K- λ ratio in bone marrow = 2:1, ratio >4:1 or <1:2 is considerd to be K or λ monoclonality. Significance = differentiate monoclonal gammopathies from reactive plasmacytosis due to autoimmune disease, metastatic carcinoma, chronic liver disease and AIDS
Radiological tests
Skeletal survey
PA view of chest, AP and lateral view of skull, AP view of pelvis, AP and lateral view of cervical, thoracic and lumbar spine, AP and lateral view of femur and humerus
Typical features: focal lytic lesions, diffuse osteopenia, pathological fractures, compression fractures of spine
Most frequent sites of involvement are sites with active haematopoiesis: skull, vertebral bodies, thoracic cage, pelvix, proximal humerus and femur
CT/MRI: routine before making dx of solitary plasmacytoma or smoldering myeloma. MRI can dwetect diffuse and focal bone marrow lesions in patiens with multiple myeloma without osteopenia or focal osteolytic lesions on standard metastatic bone surveys
PET/CT scan: FDG correlates with areas of active lytic bone disease
Specific test
Serum/urine protien electrophoresis and immiunofixation
What is treatment for multiple myeloma?
Q1: What complication has developed in this patient?
Q2: What should be the immediate management for this patient?
Q3: Why is renal failure common in multiple myeloma?
Spinal cord compression from vertebral collapse fracture
* Leads to acute onset of paraplegia, urinary and bowel incontinence
Urgent decompression spinal surgery or radiotherapy
Amyloidosis
Obstruction of distal renal tubules by protein casts Toxic effect of light chain on renal tubules
Deposition of light chain in renal glomeruli
Infection
Dehydration
Hypercalcemia
Hyperuricemia
Why are multiple myeloma patients more prone to infection?
Impaired B-cell function Neutropenia
What are the common symptoms of hyperviscosity syndrome?
Heart failure
Bleeding tendency Dizziness
Somnolence
Coma
What are the typical hematological findings in multiple myeloma?
What are the important diagnostic features of multiple myeloma?
Monoclonal paraprotein in serum
Monoclonal free light chains in urine
Monoclonal plasma cell proliferation in bone marrow
Presence of discrete lytic bone lesions
Q1: What does the ALP level suggests?
Q2: What is the most likely diagnosis?
Q3: What would you do to confirm your diagnosis?
Q4: Explain why the phosphate level is interfered in the biochemical results.
Normal ALP level suggests that the underlying cause of hypercalcemia is unlikely due to osteoblastic activity
Multiple myeloma
* C: HyperCalcemia
* R: Renal insufficiency
* A: Anemia
* B: Bone lytic lesion
Serum protein electrophoresis
Calculate serum globulin = Total protein – albumin = 58 g/L (high)
B-cells in multiple myeloma produces immunoglobulin which interferes with phosphate during the assay
