Pathology Flashcards
Disc prolapse reason
Degeneration of annulus fibrosus -> nucleus pulposus forced out
Why is spinal cord injury serious (pathological changes)
1) neuron regeneration impossible 2) primary injury will lead to secondary injury due to hemorrhage, oedema and accumulation of necrotic cells ——— 1) Neuronal and glial cell death (1º & 2º) 2) Axontomy and intrinsic changes of injured neurons 3) Demyelination 4) Glial Scars 5) Inhibit molecules 6) Poor blood supply
Occlusion of PICA
Lateral medullary syndrome (Wallenberg syndrome) 1) Spinal trigeminal nucleus -> ipsilateral facial analgesia and thermoanesthesia 2) Spinothalamic tract -> contralateral analgesia and thermoanesthesia below neck 3) nucleus ambiguus -> dysphagia, hoarseness of voice; ipsilateral paralysis of palatal and laryngeal muscles 4) sympathetic nerve -> Horner’s syndrome
Wallenberg syndrome
PICA occlusion: Lateral medullary syndrome (Wallenberg syndrome) 1) Spinal trigeminal nucleus -> ipsilateral facial analgesia and thermoanesthesia 2) Spinothalamic tract -> contralateral analgesia and thermoanesthesia below neck 3) nucleus ambiguus -> dysphagia, hoarseness of voice; ipsilateral paralysis of palatal and laryngeal muscles 4) sympathetic nerve -> Horner’s syndrome
Occlusion of vertebral artery or ASA
Medial medullary syndrome 1) medial lemniscus -> contralateral impaired sensation of position and movement and tactile discrimination 2) corticospinal tract -> contralateral hemiparesis 3) CN XII -> ipsilateral tongue paralysis; deviation to ipsilateral side when protrude
Reticular formation lesion
Loss of life function -> death Interrupt ARAS -> sleep and coma
Brown-séquard syndrome
Hemisection of spinal cord 1) ipsilateral loss of discriminative touch and proprioceptive sense below lesion (DC/ML pathway) 2) contralateral analgesia and thermoanesthesia below lesion (spinothalamic pathway) 3) loss of all sensation at the lesion level 4) ipsilateral UMN sign below lesion (corticospinal tract) 5) ipsilateral LMN sign at lesion level
Pathological manifestation of cerebellar dysfunctions
1) Ataxia and unsteady gait 2) Error in movement range and force (intention tremor, past-pointing, dysmetria) 3) Error in movement rate and regularity (dyssynergia, dysdiadochokinesia) 4) nystagmus (normally purkinje cells exert inhibitory influence to VOR neural network) 5) Delay in initiating responses 6) hypotonus
Horner’s syndrome
Lesion of spinal cord above T1 -> sympathetic ganglion damage PAM Ptosis Anhidrosis Miosis
definition of raises ICP
Elevation of mean CSF pressure above 15mmHg when measured in lateral decubitus position
Raised ICP signs
Headache (meningeal stretching) Vomiting (brainstem distortion) Cushing’s reflex (irregular respiration, bradycardia, hypertension) Unilateral mydriasis (CN III lesion) —- Infant: separation of sutures Long term: skull bone erosion, brain atrophy
Brain herniation types
1) Subfalcine/ supra callosal 2) transtentorial/ uncal 3) reverse tentorial 4) cerebellar tonsil herniation (coning) 5) transcalvarial/ fungus
Raised ICP effect consideration
1) Age 2) stage of spatial compensation 3) rate of development 4) pressure gradient
Transtentorial herniation effects
1) compress ipsilateral CN III -> mydriasis, ophalmplegia (downward outward) 2) optic nerve and retinal vein compression -> papilloedema 2) compress aqueduct of sylvius -> hydrocephalus 3) compress vital structure - midbrain and pontine infarction and haemorrhage (loss of consciousness, bradycardia, respiration changes, hypertension) 4) contralateral cerebral peduncle pushed against tentorium -> ipsilateral hemiplegia (false localising sign) 5) compress posterior cerebral artery -> ipsilateral occipital cortex infarction -> cortical blindness
Tonsillar herniation effects
Displacement of cerebellar tonsils through foramen magnum: - compression and distortion of medulla -> apnoea
Hydrocephalus definition
CSF increase in ventricles and/or subarachnoid space
Brain swelling causes
1) cerebral oedema (vasogenic, cytotoxic, hydrocephalic) 2) congestive brain swelling due to vasodilation alone (in hypoxia, hypercapnia, loss of vasomotor tone)
UNN vs LMN lesion
Location: CNS vs CNS/PNS Structure: cortex/corticospinal tract/ corticobulbar tract vs alpha motor neurons/ motor fibres in cranial or spinal nerves Distribution: groups of muscles vs segmental muscle fibres Spastic paralysis vs flaccid paralysis Hyperreflexia vs hyporeflexia Mild disuse muscle atrophy vs pronounced muscle atrophy Babinski sign vs none
Common sites of metastatic intracranial tumour
~25% Lung, breast, kidney and malignant melanoma Metastatic choriocarcinoma common in Chinese female
Primary intracranial carcinoma classified by origin
- Neuroectodermal tumours a. Glial cells (gliomas) - astrocytoma - ependymoma - oligodendroglioma - etc b. Neurons and primitive cells - neuroblastoma - medulloblastoma 2. Other structure tumours E.g. Meningioma, schwannoma, pituitary adenoma, carniopharngioma, haemangioblastomas
Supratentorial intracranial tumours
CEREBRAL LOBE AND DEEP HEMISPHERE - astrocytoma - glioblastoma - meningioma - metastatic tumours SELLA TURCICA - pituitary adenoma - carniopharyngioma
Intracranial tumours in ventricular system
Ependymoma Choroid plexus papilloma
Sites of cerebral astrocytoma, glioblastoma and oligodendroglioma
Commonly in frontal and temporal lobe; uncommon in occipital lobe
Biological malignancy of intracranial tumours
1) while histologically well differentiated, neuroectodermal tumours are rarely encapsulated and diffusely infiltrate tissues 2) may be in inoperable sites e.g medulla, pons, midbrain or deep hemisphere 3) may become histologically malignant with years, esp astrocytoma to glioblastomas multiforme
Spread of poorly differentiated neuroectodermal tumours
Spread within brain and spinal cord, by direct infiltration or CSF spread Rarely metastasise outside CNS
Most common site for adult intracranial tumour
Supratentorial in the cerebral lobes (70%)
Common CNS tumour and site in children
70% infratentorial Posterior fossa in midline, usually: - Cerebellum (astrocytoma, medulloblastoma) - brainstem (astrocytoma, ependymoma)
Astrocytoma histological types
Protoplasmic Pilocytic Gemistocytic Fibrillary
Astrocytoma grading
1 to 4 Grade 2: Nuclear pleomorphism (astrocytoma grade 2) Grade 3: mitotic activity (anaplastic astrocytoma) Grade 4: necrosis, endothelial hyperplasia (glioblastoma multiforme)
Astrocytoma gross appearance
Diffuse infiltration thus no clear border Cerebral astrocytoma: diffuse enlargement of region Cerebellar astrocytoma: cystic with proteinaceous fluid
Glioblastoma multiforme histology
- Variable histology - pseudo palisade - central necrosis zone surrounded by degenerate tumour with extensive cytoplasmic pleomorphism - endothelial hyperplasia
Oligodendroglioma gross and histo
Grossly well differentiated with little necrosis Histo: box like cells with clear halo Well marked cell border Calcification common
Ependymoma gross and histo
Gross: mass protruding into ventricles, encapsulated Histo: - rosette (cuboidal tumour cells around central lumen) - pseudo rosette (pink Fibrillary halo around vessels) - spindle cells - blepharoplasts
Medulloblastoma histo
Good radiotherapy response Histo: - small cells - densely stained ovoid nuclei - little cytoplasm - rosette formation with Central Fibrillary extension
Meningioma Gross and histo
Well circumscribed and lobulated Histo: - cellular whorls - psammoma bodies Site: parasagittal, fall cerebri, base of skull, inner surface of calvaria
Schwannoma sites
Most commonly cranial nerve roots: - Vestibulocochlear nerve - Trigeminal nerve Can be in spinal nerve root or peripheral nerve
Schwannoma histo
Antoni type A & B (Read)
Xerostomia definition and cause
Def: USF reduce by 50% Cause: 1) water or electrolyte loss 2) damage to salivary gland 3)interference with neural transmission
Rhinitis classifications
Allergic rhinitis Infectious rhinitis Occupational rhinitis Drug induced rhinitis
Sinusitis radiological finding
X Ray: -air fluid level -sinus opacification
Sinusitis complication
Extension of infection to: Orbital cellulitis Orbital abscess Cavernous sinus thrombosis
Sinusitis pathogenesis
Anatomical or functional obstruction of normal mucociliary clearance of sinuses -> Fluid accumulation in sinus or ostemeatal complex -> Infection
Otitis media pathogensis
Ear canal skin inflammation Swelling blocking rapid cell turnover More dead skin produced, which allow germ breed Pus filled ear canal Tympanic membrane bulge outwards, leading to pain, fever, hearing loss (AOM) Tympanic membrane bursts and perforation, discharge of pus (active CSOM) Perforation persists, discharge stops (inactive CSOM)
Otitis media complications
TM rupture with pus discharge Mastoid abscess if pus moves in Facial nerve palsy or CN VI Brain abscess
Otitis media pathogens
Viral or bacteria (S pneumoniae, HI)
Tonsillitis pathogen
Bacterial: s pyogenes, Staphylococci, S pneumoniae, HI Viral: rhinovirus, adenovirus, EBV Others: diphtheria, syphilis, TB, candida
Clinical features of tonsillitis
Fever Sore throat Odynophagia Otalgia Trismus Red swollen tonsils Throat redness Swollen uvula Gary furry tongue Whitish spots ALWAYS BILATERAL
Sialoadenitis pathogensis
1) ascending duct infection related to dehydration and debilitation e.g. Old age –> thicker more mucous salvia that stuck in ducts –> infection OR 2) secondary to ductal obstruction e.g. Stones (submandibular duct most likely)
Sialoadenitis pathogen
Viral: Mumps Coxsackievirus HIV Echovirus Bacterial: Staphylococcus TB Syphilis No infectious: Sjogren’s
Acute epiglottitis presentation
Children 2-4 yo Fever Severe sore throat Stridor Dysphonia Drooling Laryngoscopy: cherry red epiglottis XR neck: thumb sign Blood culture: HIB
HI microbiology
Gram negative Beta lacamase producing Coccibacilli Factor V and X for growth Type a to f, b most invasive
Epiglottitis management
Airway protection Antibiotic (amoxiclav) Rifampicin prophylaxis HIB vaccination
Quinsy presentation
Adolescents and young adults Low grade fever Severe sore throat Stridor (if bilateral) Dysphagia Medial deviation of tonsils
Epiglottitis pathogen
HiB
Quinsy pathogen
GAS (strep pyogenes) Mixed oropharyngeal organisms: anaerobes, viridans streptococcus
GAS microbiology
Beta hemolytic Lancefield group A Bacitracin sensitive
Strep pneumoniae microbiology
Alpha hemolytic Optochin sensitive Bile soluble
Croup (laryngotracheobronchitis) presentation
Young children of 3 months to 3 yo Fever Barking cough Tripod position Hoarseness Stridor XR neck: subglottic swelling - hourglass or steeple sign Nasopharyngeal aspirated (NPA) - viral antigens
Quinsy management
Airway protection Antibiotic Abscess drainage
Croup pathogen
Viral mainly: Parainfluenza Influenza Respiratory syncytial Adenovirus Rhinovirus Mycoplasma
Croup management
Airway protection Racemic adrenaline +- steroid
Deep oropharyngeal fascial space infections
1) submandibular and sublingual space (Ludwig’s agina) 2) lateral pharyngeal space 3) retropharyngeal space
Ludwig’s angina presentation
Board like floor swelling High fever Systemic toxicity Dysphagia Often with dental root abscess
Ludwig’s angina management
Airway protection Antibiotic Soft tissue decompression Dental assessment
Lateral pharyngeal space infection presentation
Fever Sore throat Dysphagia Neck stiffness Jaw angle swelling Great pain and trismus (if ant) Great dyspnea (if post) CT/MRI to see extension Blood culture Pus culture
Lateral pharyngeal space infection complications
Jugular venous thrombophlebitis Carotid artery erosion
Lateral pharyngeal space infection management
Airway protection Antibiotic Surgical drainage (if abscess) Treat primary infective focus
Prothrombin time
Extrinsic and common pathway -> I, II, V VII X
APTT
Activated partial thromboplastin time Intrinsic and common pathway -> all factors except VII and XIII
Thrombin time
Fibrinogen deficiency or dysfunction Thrombin inhibition e.g by heparin
Bleeding disorder lab tests
PT APTT TT fibrinogen level Platelet tests -> platelet count, platelet function test by aggregometry, skin bleeding time
Platelet disorder presentation and classes
All present with mucocutaneous bleeding Autoimmune thrombocytopenia Alloimmune thrombocytopenia -neonatal allo TP -post transfusion purpura -platelet refactoriness Inherited -Bernard-soulier syndrome -grey platelet syndrome -storage pool disease -glanzmann’s thrombasthenia DIC dilutional (eg after massive transfusion)
Haemophilia A gene linkage
Long arm of X chromosome -> x linked Maternal side 1/3 are due to spontaneous mutation
Haemophilia A and B problem
Haemarthrosis -> recurrent bleeding in major joints leading to progressive joint deformity Inhibitor to infused factor concentrate -> replacement therapy less effective High cost of treatment Transfusion transmitted infection (esp viral HIV HBV HCV) Carrier female detection
VWD genetic
Short arm of chromosome 12
VWD lab test
Increased APTT Increased bleeding time VWF antigen assay Ristocetin assay Collagen binding assay Factor VIII assay
Other hereditary coagulation disorder
Deficiency of VII XII X fibrinogen Autosomal recessive
Vit K deficiency causes
Obstructive jaundice Malabsorption Post oral broad spectrum antibiotics that killed intestinal flora
Haemorrhagic disease of newborn
Immature liver that cannot perform K dependent post translation gamma carboxylate on of glutamic acid on II VII IX X C S sterile gut with no intestinal flora for K production Low vit K in breast milk
INR
International normalised ratio INR = (PT/ mean normal PT)^ ISI ISI is international sensitivity index Used for monitoring oral anticoagulant so no vitamin K antagonism occur
Vitamin antagonism
Result of oral anticoagulant usage Competitive inhibitor of vitamin K epoxide reductase needed for recycling vitamin k during gamma carboxylation
Liver disease and bleeding aetiology
Reduced hepatic synthesis of clotting factors and inhibitors (except VIII and VWF) Reduced vit K absorption due to cholestasis -> further decrease clotting factor production Failure of reticuloendothelial cells to clear activated products and intermediates of coagulation and fibrinolysis -> interfere with platelet function and fibrin formation Portal hypertension -> hypersplenism -> platelet sequestration Acquired dysfibrinogenaemia -> abnormal fibrinogen synthesis
Liver induced coagulation disease treatment
Parenteral vit K replacement Clotting factor replacement via FFP
Uraemia and bleeding tendency aetiology
Defect in platelet function (inhibition by nitric oxide) Low haematocrit -> Platelet-vessel wall interaction
How to treat uraemia bleeding tendency
Increase haematocrit by red cell transfusion erythropoietin therapy Peritoneal or haemodialysis DDA VP administration Cryoprecipitate transfusion
DIC pathogenesis
Entry of tissue thromboplastin into blood stream Direct activation of coagulation Severe endothelial injury Direct activation of platelet Thrombin activation which convert fibrinogen to fibrin, activating secondary fibrinolysis Widespread coagulation —> intravascular fibrin formation —> micro thrombotic occlusion of small vessels —> tissue ischaemia and multi organ dysfunction Widespread coagulation and fibrinolysis depletes clotting factors, platelets and coagulation inhibitors —> severe bleeding
Causes of DIC
Infection (septicaemia and viral infection) Trauma (serious tissue injury, fat embolism, extensive burns) Cancers (acute promyelochtic leukemia, metastatic carcinoma) Obstetric condition (septic abortion, amniotic fluid embolism, abruptio placentiae) Immunological (haemolytic blood transfusion reaction eg ABO incompat; organ transplant rejection)
DIC diagnosis
Underlying related condition Increase PT APTT TT Reduced fibrinogen level, low antithrombin Thrombocytopenia Increase fibrin degradation product namely D-dimers from secondary fibrinolysis Microangiopathic change in blood film as RBC damaged when passing through clots
DIC. Management
Platelet transfusion FFP to replenish clotting factors Anticoagulants (to overt thromboembolism or extensive fibrin deposition) Antithrombin concentrate *** treat precipitating trigger first!!
IPEX
Autoimmune disease X linked single gene deletion Immune dysfunction Polyendocrinopathy Enteropathy X linked Deletion in foxp3 transcription regulator -> loss of Treg cells (Cd4 Cd25 foxp3)
Autoimmune aetiology
Lack of Treg cells (IPEX) Release of sequestrated antigens (sympathetic ophthalmia, vasectomy) Induction of MHC II antigen on non-APC (interferon gamma on thyroid epithelial cells) Cross reaction between microbial antigen and similar autoantigen (rheumatic heart disease)
Autoimmune disease factors
Genetic Hormonal Environmental (infective, drug)
Genetic factors in autoimmune
Demonstrates familial clustering and higher concordance rate in identical twins No clear mandelian traits Multiple genes involve with low penetrance Genetic heterogeneity MHC gene esp associated -> HLA-DR4 and rheumatoid arthritis; HLA-DR3/4 and IDDM
Hormonal factors in autoimmune
Sex preponderance in many SLE female:male = 9:1 (admin of male sex hormone and female castration helps with SLE in mice)
Infective factor and autoimmune
IDDM and rubella or enterovirus infection
Drug induced autoimmune
SLE - hydrallazine, penicillamine Hemolytic anaemia - methyldopa
Environment factor and autoimmune
Drug, infection SLE -> Sun exposure
Neutrophilia causes
1) infection (bacterial fungal) 2) Acute inflammation 3) tissue damage/ infarction 4) MPN 5) drugs eg corticosteroids
Neutropenia causes
Infection (neonate) Leukemia, metastases Aplastic anaemia Drugs Myelofibrosis Cyclical
Lymphopenia causes
HIV AIDS Drugs eg corticosteroid
Lymphocytosis causes
Children: Viral infection (CMV), sometimes bacterial (pertussis) Adolescent: Viral (EBV) Adult: Chronic lymphocytic leukemia, acute stress
Eosinophilia causes
Allergy Parasitic infection Drug hypersensitivity Autoimmune Neoplasm
Basophilia causes
Chronic myelogenous leukemia (CML) Acute leukemia
Monocytosis
Chronic infection eg TB chronic inflammation Neoplasm: CML, other MPN MDS
Crude Haematological findings in AML ALL CML CLL and MDS
AML -> presence of blast cells; auer rods ALL -> blast cells CML -> basophilia, mature and immature CLL -> abnormal mature looking lymphoid cells MDS -> funny looking white and red cells; abnormal nucleus shape
Functional white cells disorders
Lazy leukocyte syndrome -> defect in chemotaxis Opsonin deficient -> defect in phagocytosis Chronic granulomatous disease, myeloperoxidase deficiency -> defect in killing or digestion
WBC disease investigations
1) PBS, CBC 2) Bone marrow - BMA or - touch imprints - trephine biopsy 3) cytochemistry staining - non specific esterase (AML) - myeloperoxidase (AML) - PAS (ALL) 4) flow cytometry 5) lymph node / other tissue biopsy 6) cytogenetic karyotypin 7) FISH 8) PCR
Both quality and quantity abnormality WBC disorder
B cell - X linked agammaglobulinaemia - severe combined immunodeficiency T cells - DiGeorge syndrome - MHC class II deficiency
Multiple myeloma (presentation, diagnosis)
Plasma cell neoplasm Present as: Anaemia Bone pain Recurrent infection Renal failure PBS-> rouleaux formation; no abnormal white cells Bone marrow-> plasma cells 30% and clinal Urine/ serum -> monoclonal protein
BMA usage in WBC disorder diagnosis
Assessment of BM cellularity and differential counts Identification of abnormal cells Stain with Wright-Giemsa stain
BM trephine biopsy usage in WBC disorder diagnosis
Assess BM cellularity Identification of abnormal cells Assess architecture and topographic relationship of cells in BM staging of lymphoma
Cytogenetic karyotyping limitations
There might be no metaphase cells
What is a blood cancer
Malignancy arising from haematopoietic system or lymphpoietic system
Lymphoma definition
Clonal malignancy of lymphoid system (ie from lineage B cells T cells NK cells)
Aetiology of lymphoma
Increase with age Related to viral infection - EBV, HIV HTLV human T cell lymphoproliferative virus
Lymphoma manifestation
1) enlargement of nodal (lymph node) or extranodal tissues 2) A symptoms -> asymptomatic 3) B symptoms -> systemic, eg Fever, night sweats, loss of body weight
Lymphoma classifications
Hodgkin lymphoma B cell lymphoma T cell lymphoma NK cell lymphoma
Lymphoma metastasis
Via lymphatics (Hodgkin) Hematogenous spread in other types of lymphoma Local infiltration to different organs
B cell lymphoma treatment
1) R-CHOP chemotherapy + targeted therapy Rituximab anti CD20 cyclophosphamide, hydroxydaunorubicin, vincristine [Oncovin], prednisone (Purine analogue containing regimen for low grade; mab for maintenance treatment) 2) HSCT autologous HSCT for relapses lymphoma (Source from peripheral blood, BM) If there is BM involvement, then allogenic HSCT
Hodgkin lymphoma treatment
1) chemotherapy with/wo radiotherapy 2) Mab against CD30 for relapse 3) autologous HSCT for relapse
NK lymphoma treatment
1) chemotherapy, esp L-asparaginase containing regimen 2) otherwise similar to B cell
T cell lymphoma treatment
Similar to B cell lymphoma 1) early use of autologous HSCT may be useful
Hodgkin lymphoma nature
Less common in Chinese Good prognosis; most patients curable
NK cell lymphoma nature
Found mainly in Asians (ninja!) Nose affected as main site EBV related Highly aggressive with poor prognosis
T cell lymphoma nature
Uncommon Variable prognosis Related to HTLV-1 (Japan and TW)
Lymphoma prognosis
1) International prognostic index -tumour stage - serum LDH - extranodal sites - age -performance 2) Histology types -lineage - high/low grade 3) chemotherapy intensity
AML clinical features
-adults -myelosuppresion -> anaemia and thrombocytopenia -leucocytosis with >20% blasts in BM and blood -associated with toxic exposure, toxic drugs and antecedent myelodysplastic syndrome - Auer rods
AML treatment
Induction of remission Consolidation of remission with high doses of chemotherapy Maintenance of remission usually not given HSCT for relapse or high risk cases All trans retinoids acid and arsenic trioxide for acute promyelocytic leukemia
ALL clinical features
-mainly adults, sometimes children - leucocytosis -myelosuppresion -> anaemia and thrombocytopenia -enlargement of lymph nodes, liver and spleen as lymphoblastic cells return to origin - CNS involvement -not obviously associated with toxic exposure B cell origin?
ALL treatment
Induction of remission Consolidation chemotherapy Maintenance treatment for 2 years CNS prophylaxis HCST transplant in relapse or high risk
CML clinical features
-adults; incidence increase with age -leucocytosis with mature and immature cells, basophilia -enlarged liver and spleen -associated with irradiation exposure eg atomic bomb -triphasic if untreated: 1) chronic 3-4y 2) acceleration <6m 3) blastic crisis 1-2 months -Philadelphia gene - BCR-ABL 9-22 translocation (cytogenetic karyotyping or FISH or PCR)
CML treatment
Chemotherapy ineffective Targeted therapy with tyrosine kinase inhibitors (eg imatinib dasatinib bosutinib I’m da boss) Hydroxyurea for symptomatic treatment HSCT for blastic transformation patient or not responding to TKI
CLL clinical features
-elderly, never in childhood -uncommon in Chinese -late stage myelosuppresion -> anaemia and thrombocytopenia -lymph node enlargement, late stage liver and spleen enlargement -leucocytosis with mature cells -associated with toxic exposure, toxic drugs and antecedent myelodysplastic syndrome
CLL treatment
No early stage treatment Chemotherapy with Purine analogue (oral alkylation agent not preferred in <50
MDS clinical features
Pancytopenia Hyper cellular BM Myelodysplastic blood cells in blood or BM BM abnormal karyotyping Increased blasts Progress to AML Associated with previous chemotherapy irradiation or toxic exposure
MDS classes
Refractory cytopenia with unilineage dysplasia Refractory cytopenia with multilineage dysplasia Refractory anaemia with ringed sideroblasts Refractory anaemia with excess blasts MDS with 5q- Childhood MDS
MDS diagnosis
PBS CBC -> pancytopenia BMA -> hypercellularity Cytogenetic -> monosomy 5 or 7, deletion of long arm of 5 or 7 5q- 7q-
MDS management
1) risk stratification 2) supportive, transfusion for most - erythropoietin for anaemia - iron chelation for chronic transfusion 3) allogeneic HSCT in younger patients for RAMD RAEB 4) lenalidomide for 5q- syndrome 5) demethylating agents (eg azacytidine decitabine)
MDS prognosis
Incurable except in young patients after HSCT May transform to AML, especially in RAEB
MPN features
Clonal disease of pluripotent HSC 1) increased circulating cells of all haematopoietic lineages 2) hypercellularity in BM 3) absence of muelodysplastic features Pre-leukemia
MPN common subtypes
CML -> myeloid Polycythaemia Vera -> erythroid Primary myelofibrosis -> fibrous tissue Essential thrombocythaemia -> megakaryocytic
MPN genetic mutations
CML -> BCR-ABL1 PV -> JAK2 MF -> 50% JAK2; 40% CALR ET -> 50% JAK2; 40% CALR CALR = calreticulin gene
PV features
MPN *) pruritus 1) high Hb -> facial plethora 2) leucocytosis thrombocytosis 3) splenomegaly 4) suppressed serum erythropoietin diagnosis by exclusion JAK2 mutation
PV treatment
Venesection -> replace venesected blood with normal saline Cytoreduction with hydroxyurea Avoid secondary leukemia inducing agents eg alkylating agents or radioactive phosphorus Thrombosis prophylaxis eg aspirin
Primary myelofibrosis features
- Hepatosplenomegaly; Extramedullary hematopoiesis, which is non functional Leuco-erythroblastic picture with tear drop RBC JAK2, CALR mutation Diffuse fibrosis of BM -> megakaryocytic proliferation Terminally present with hepatic fibrosus -> variceal bleeding and portal hypertension CELLULAR PHASE (prefibrotic) -anaemia -leucocytosis -thrombocytosis FIBROTIC PHASE -pancytopenia
Primary myelofibrosis management
1) supportive 2) early splenectomy helps to decrease blood transfusion requirement 3) alligeneic HSCT in younger patient 4) JAK2 inhibitor for high risk 5) Cytoreduction with hydroxyurea 6) avoid secondary leukemia inducing agents eg alkylating agents or radioactive phosphorus
ET features
Sustained thrombocytosis (must exclude chronic inflammatory disorder, infection, neoplasm) JAK2 CALR mutation
ET treatment
Treatment not required in young patient Prophylactic anti thrombotic agents eg aspirin esp in elderly Cytoreduction with hydroxyurea Anagrelide to reduce platelet count Avoid leukarmogenic agents eg alkylating agents or radioactive phosphorus
MDS/MPN feature
Increased circulating cells Hypercellularity of BM Myelodysplastic features of blood cells
MDS/MPN classification
Chronic myelomonocytic leukemia (CMML) atypical chronic myeloid leukemia (aCML)
CMML features
Elderly Monocytic lineage proliferation High monocyte count No Philadelphia chromosome
Cortical lesion of S1
Contralateral loss of discriminative touch and position sense; thermoception and nociception relatively unaffected
Lesion of association somatosensory cortex
Tactile agnosia - inability to recognise object despite sensation Constructional apraxia - deficit in ability to relate extra personal space Neglect syndrome (contralateral) Spatial orientation difficulty eg map reading, driving
MDS/MPN management
Supportive in elderly patients Allogeneic HSCT in children Tyrosine kinase inhibitor for some CMML
Thalamic pain syndrome
Lesions in the Ventral Posterior nuclei of thalamus (VPM, VPL) Analgesia followed by paraesthesia and hyperalgesia or even severe spontaneous pain; associated with exaggerated affective response
Lesion of M1
Interferes with motor proficiency and manual dexterity Independent control of fingers may be lost (corticospinal tract)
Lesion of PMA
Paresis or weakness of axial and proximal muscles (medial descending system) Interfere with choreography of complex movement (complex movement possible but slow execution) Severely affects visually guided movement
Lesion of SMA
Interferes with goal-directed behaviours that require planning and execution of complex motor sequence e.g. circumventing a transparent screen deficit in bimanual coordination
Unilateral UMN lesion of corticobulbar tract
No symptoms for CN III IV V VI upper face (VII) IX X XI Contralateral symptoms for lower face VII (e.g. lower face paralysis, sagging mouth corner obicularis oris) and XII (tongue deviate to contralateral side of lesion)
Unilateral LMN lesion of corticobulbar tract
Ipsilateral LMN symptoms for cranial nuclei III-XIII except VIII
Unilateral supranuclear facial paralysis
UMN lesion of corticobulbar tract Contralateral lower face paralysis (sagging mouth corner - orbicularis oris)
Unilateral peripheral facial paralysis
LMN lesion of corticobulbar tract Ipsilateral upper and lower face paralysis (incomplete closure of eyelid - obicularis oculi; sagging mouth corner - orbicularis oris)
Lentico-striate artery occlusion
Leads to capsular infarction/ haemorrhage -> internal capsule function affected UMN paralysis of contralateral limbs and lower face
Causes of UMN lesion
Lentico-striate artery occlusion -> capsular infarction MCA infarction Pontine infarction Corona radiata tumour etc.
UMN vs LMN lesions
CNS vs CNS/PNS Involve cortex, corticospinal or corticobulbar tract vs alpha motor neuron, motor fibres of cranial or spinal nerves Distribute to groups of muscles vs segmental muscles Spastic paralysis (antigravity muscle, clasp-knife rigidity) vs flaccid paralysis Hyperreflexia vs hyporeflexia Mild disuse atrophy of muscle vs pronounced atrophy Babinski’s sign vs no Babinski’s sign
Lesion above red nucleus (midbrain)
Decorticate posturing: Rubrospinal cord intact, therefore UL flexion (elbow and wrist flexed) - wrist flexed - leg extended - plantar flexion
Lesion between red nucleus and vestibular nucleus
Decerebrate posturing/rigidity Unopposed pontine reticular nucleus and vestibular nuclrus -> extensor activities –> UL extension (extension of elbow, pronation) - wrist flexed - leg extended - plantar flexion
Visual field defect in optic nerve lesion
Monocular amaurosis (ipsilateral) e.g. in optic neuritis
Visual field defect in optic chiasma lesion
Bitemporal hemianopia e.g. pituitary macroadenoma
Visual field defect in optic tract lesion
Homonymous hemianopia (contralateral side of visual field busted in both eyes) e.g. craniopharyngioma
Visual field defect in optic radiation lesion
Temporal: homonymous upper quadrantic hemianopia Parietal: homonymous lower quadrantic hemianopia
Visual field defect in visual cortex lesion
Dense homonymous hemianopia with macular sparing
Prefrontal cortex lesion
- primitive reflex(grasp, snout, suck, rooting) - high distractibility - lack of foresight/insight - inability to switch tasks - lack of ambition/ responsibility - lack of social propriety and self-monitoring
Limbic lesion
- Amnesia - Flat emotion/ affect - Akinetic mutism
Types of aphasia
Expressive (Broca’s) non-fluent Receptive (Wernicke’s) fluent Global
Mental retardation defintion
2 SDs less than mean intelligence; never had a normal IQ
Dementia definition
loss of previously acquired intelligence
Causes of dementia
1) Primary neurodegenerative dementia - alzheimer’s - Lewy bodies 2) Vascular dementia - infarct ——–uncommon— 3) Infective dementia - e.g. syphilis, AIDS, CJD 4) Intracranial pathology - tumour - hydrocephalus - subdural hematoma 5) Chronic alcoholism etc.
Vascular dementia
History of stroke Abrupt decline Focal neurological signs Management: Stroke prevention
Spinal cord injury repair strategy
1) Neuronal and glial cell death (1º & 2º) - reduce cell death with methylprednisolone - block death receptor activation to reduce 2º injury - Stem cell transplant to replace neurons 2) Axontomy and intrinsic changes of injured neurons - Enhance regeneration by modifying intrinsic environment e.g. increase cAMP, inhibit PKC 3) Demyelination - Oligodendrocyte or Schwann cell transplant 4) Glial Scars 5) Inhibit molecules 6) Poor blood supply - reduce glial scar and inhibit molecules by enzymes, antibodies
Ectopic Thyroid Tissue
may be found anywhere along the path of descent of the thyroid gland. It is commonly found in the base of the tongue or with the lateral cervical lymph nodes.
Thyroglossal duct cyst
found anywhere along the path of descent of the thyroid gland, but always in the midline of the neck Sometimes connected to the outside by a canal, a thyroglossal fistula
Ectopic parathyroid tissue
persist along the path of migration (may be as low as aortic arch) Can be visualised by Parathyroid scintigraphy dual phase planar imaging
Parathyroid scintigraphy dual phase planar imaging
Patients are injected with tracer (Tc99m, Technetium -99m) and imaged at 5 min and images repeated at 2h. This radiotracer is taken up by the thyroid gland, but cleared from the thyroid with a half-life of 30 min. It is usually retained by abnormal parathyroid tissue
Recurrent laryngeal nerve injury
(normally supplies all laryngeal muscles except cricothyroid; especially important as it innervates superior cricoarytenoid muscle, the only abductor of vocal cords) Unilateral: Hoarseness, dysphagia, partial (abductor) paralysis of the vocal cord Bilateral: Bilateral (abductor) paralysis of vocal cord, airway obstruction, which may leads to death
Pituitary adenoma classification
1) By size: Macroadenoma 1cm+; microadenoma 1cm - 2) - Functional (hormone overproduction with clinical manifestation) or - silent (hormone overproduction without clinical manifestation) or - hormone negative
Pituitary adenoma histology
Monotonous pinkish secretory cells - uniform polygonal cells in sheets/cord Rare mitosis, little pleomorphism Increased vascularity
GH hypersecretion causes
PRIMARY: 1) pituitary adenoma (acidophil cell tumour) SECONDARY: 1) Hypothalamic tumour releasing GHRH 2) Ectopic GH or GHRH from lung cancer or pancreatic cancer
GH hypersecretion pathology
Gigantism in children; Acromegaly in adults Symptoms: 1) outgrowth of all organs, bones, joints and soft tissues (excessive height in gigantism; skeletal overgrowth with large nose feet hands on acromegaly) 2) hyperglycaemia (osmotic diuresis?)
GH deficiency causes
PRIMARY: 1) idiopathic in childhood 2) Pituitary tumours e.g. Silent or hormone negative pituitary adenoma; carniopharyngioma
GH deficiency pathology
Pituitary dwarfism in children Symptoms: 1) delayed physical maturation 2) short stature 3) reduced skeleton and muscular mass - affected walking jumping and standing 4) sparse hair growth and frontal recession
GH secretion tests
1) Blood test for GH or IGF-1 - difficult as t1/2 is short 2a) Functional test - stimulation test - insulin tolerance test - arginine infusion test 2b) functional test - suppression test - glucose tolerance test
GH deficiency functional test
Arginine infusion test and insulin resistance test Arginine and insulin normally reduces plasma glucose, thus increasing GH secretion -> if GH not increased, GH hyposecretion
GH over secretion functional test
Suppression test (glucose tolerance test) Increased glucose normally lead to reduction of GH secretion If GH level not decreased, then GH hypersecretion
Hyper prolactinemia causes
PRIMARY: 1) prolactinoma (a pituitary adenoma) SECONDARY: 1) pregnancy 2) psychiatric medications
Hyper-prolactinemia symptoms
Men: loss of libido, impotency, low sperm count, gynaecomastia Women: menstrual disturbances (amenorrhea), galactorrhea, loss of libido, infertility
ACTH hypersecretion causes and pathology
Cause: pituitary adenoma Pathology: Cushing’s disease (secondary hypercortisolaemia) - ACTH and Cortisol increased - symptoms: Cushing’s syndrome
Cushing’s disease definition
Hypercortisolaemia (Cushing’s syndrome) caused by increased ACTH production due to pituitary adenoma
ACTH hyposecretion causes and pathology
Causes: inefficient pituitary production; or use of exogenous steroids Pathology: secondary hypocortisolism (secondary adrenal insufficiency) - reduced ACTH and cortisol - Nausea, vomiting - fatigue, weakness, hypotension - hyperpigmentation and hyperkalemia NOT SEEN
TSH hypersecretion causes and pathology
Cause: pituitary adenoma Pathology: secondary hyperthyroidism - increase TSH and TH
TSH hyposecretion pathology
Secondary hypothyroidism - decrease TSH and decrease TH
LH and FSH hyposecretion
Hypogonadotropic hypogonadism female: - breast atrophy - vaginal dryness - reduced libido Male: - reduced libido - impotency
Panhypopituitarism
Where all pituitary hormones are insufficient GH, Prolactin, FLAT
Causes of hypopituitarism (especially Panhypopituitarism)
1) post surgery or radiation 2) trauma 3) infection/ inflammation 4) pituitary tumour (silent/ hormone negative) 5) Sheehan syndrome
Sheehan’s syndrome
Aka postpartum hypopituitarism - caused by ischaemia necrosis of pituitary gland due to blood loss during or after childbirth
ADH deficiency due to hypopituitarism
- Neurogenic diabetes insipidus (polyuria, polydipsia) - hypernatremia
Diabetes insipidus classes
1) Neurogenic DI (decreased ADH release due to hypopituitarism) 2) nephrogenic DI (inability of kidney to respond to ADH) 3) Dipsogenic (defect in hypothalamic thirst mechanism) 4) Gestational (placenta produce vasopressinase that cleaves ADH)
Pancreatic islet cell tumours classifications
A. FUNCTIONAL: 1) insulinoma (beta cells) 2) gastrinoma (G cells) 3) glucagonoma (alpha cells) 4) VIP-oma (VIP cells) B. NON-FUNCTIONAL