Hematopathology Flashcards
1
Q
MCV
A
- Mean Cell Volume (MCV): average volume of RBC
- femlolitres
2
Q
MCH
A
- Mean Cell Hemoglobin
- pg
3
Q
MCHC
A
- Mean Cell Hb Concentration
- g/dL
4
Q
RDW
A
- RBC Distribution Width -> cell size variation
- coefficient of variation of RBC vol.
5
Q
Ferritin & TIBC
A
- whenever ferritin decr, TICB incr
- TIBC measures Transferrin
- nl % Transferrin iron sat. = 33%
6
Q
Hemolytic anemias
A
- RBC lifespan decreased
- Increased erythropoeitin & erythropoesis
- Accumulation of Hb breakdown products
7
Q
Intravascular hemolysis
A
- Mechanical injury to vessels: Ex. defective heart valves, microthrombi
- Complement fixation: Ab-coated RBC
- Infections: ex. clostridia, malaria, other parasites
- Sx (Pathoma):
- Hemoglobinemia
- Hemoglobinuria
- Hemosdierinuria
- decr serum haptoglobin
8
Q
Extravascular hemolysis
A
- RBC rendered less deformable: ex. spherocytosis, sickle cell disease
- RBC rendered foreign: ex. Ab-coated
9
Q
Lab evidence of hemolytic anemia
A
- PB: normochromic, normocytic anemia; polychromasia
- BM: erythroid hyperplasia
- Plasma/serum: incr bilirubin (unconjugated); incr LDH; decr haptoglobin
- Urine: hemosiderouremia +/- hemoglobinuria
10
Q
A
Hereditary spherocytosis
- intrinsic hemolytic anemias; extravascular predominant
- AD, highest incidence in N. Europe
- mutations in RBC membrane proteins
- ankyrin
- band 3
- band 4.2
- spectrin
- Morphology: RBC loses ability to deform and becomes spheroid
- No central area of pallor, normochromic normocytic
- Etiopath: reduced RBC membrane stability
- small fragments loss during shear stress
- RBC become more spherical
- stuck in splenic sinusoids
- phagocytosis by splenic macrophages -> splenomegaly
- Sx: most cases mild to moderate hemolytic anemia
- infections can induce aplastic or hemolytic crises
- Complication:
- cholelithiasis
- incr risk of aplastic crisis w B19 infection (Pathoma)
- Dx:
- incr MCHC
- incr RDW
- osmotic fragility test: in 65% of HS cases, red cells lyse prematurely in increasing hypotonic solution
- Rx: splenectomy
- anemia resolves
- spherocytes persists however
- Howell-Jolly bodies emerge on blood smear (Pathoma)
11
Q
A
G6PD Deficiency: pathophys
- G6PD A- (10% Blacks); variant (mild)
- G6PD Mediterranean; markedly reduced T1/2 of G6PD
- X-linked recessive
- Etiopath: abnormally folded protein susceptible to proteolytic degradation
- decr G6PD enzyme activities leads to less protection from oxidant stress.
- oxidation of SH groups on globin of Hb
- ppt of denatured globin called Heinz bodies (ppt Hg)
- Glutathione remains in oxidative state; Glutathione needs to be in reduced state to scavenge free radicas -> Bleaching or oxidation of Hb produce Heinz bodies
- If membrane is less damaged, bite cells, helmet cells, and spherocytes,
- Both intravascular (predominant) and extravascular hemolysis
- Sx:
- acute hemolysis
- neonatal jaundice (rare and due to RBC degradation & unconjugated bilirubin)
- chronic low-grade hemolytic anemia
- back pain (Hb is toxic; Pathoma)
12
Q
A
Etiopath:
- deoxygenated HbS aggregate and polymerize
- futher deoxygenation causes sickling
- Predominantly extravascular hemolysis
- factors affecting sickling
- amount of HbS present and its interaction w other Hb chains
- HbF and HbA decr sickling
- HbC (abnormal, E6K mutation) incr. sickling on Beta-globin
- Hb concentration
- dehydration induces sickling
- presence of alpha-thal decr. sickling
- Acidity and Low O2 incr. sickling
- Triggers: high altitude, hypoxia, exercise,
- amount of HbS present and its interaction w other Hb chains
Sx
- chronic hemolysis
- hemolytic anemia
- dactylitis: swollen hands and feet due to vaso-occlusive crisis; common sign in infants (Pathoma)
- extramedullary hematopoiesis (crew cut skull X-ray)
- frontal bossing due to hyperplastic BM
- hypersplenism -> repeated infarction & fibrosis -> autosplenectomy -> prone to infections by encapsulated bacteria
- incr. bilirubin (jaundice), gallstones
Complications
- vaso-occlusive crisis
- acute chest syndrome, stroke, kidney damage, acute infarction of BM
- aplastic crisis due to B19 and other viral infections; most common cause of death in children
- sequestration crisis: pooling of blood in spleen
- autosplenectomy leads to shrunken, fibrotic spleen (Pathoma from this point on )
- incr risk of infection w encapsulated organisms (Strep pneumoniae)
- incr risk of S. paratyphi
Dx: based on Hx
- PB smear showing target cells
- Hb electrophoresis
- Prenatal DNA screening
- Howell-Jolly bodies on blood smear
- Metabisulfite screen: causes cells with any amount of HbS to sickle (both in trait and disease)
Rx
- supportive, analgesics, rehydration
- hydroxyurea to stimulate HbF production
- folate supplementation
- bone marrow transplanation
- penicillin for prophylaxis
13
Q
A
beta-Thal MAJOR
- hypochromic microcytic anemia
- decr survival of RBC and RBC precursor
- extramedullary hematopoiesis (frontal bossing, hair on end skull)
- incr iron absorption
Sx
- beta-thal major: severe transfusion-dependent anemia
- beta-thal minor: asx mostly
- beta-thal intermedia: milder variants of 1, severe variants of 2, or 1 combined w alpha-thal
Complications
- hemosiderosis & 2o hematochromosis
- congestive cardiomyopathy
- hepatosplenomegaly due to extravascular hemolysis & extramedullary hematopoiesis
- growth retardation & death unless given regular blood transfusions
Dx
- presents @ 6 to 9 mo post-natal
- Hb levels = 3 to 6 g/dL
- HbF markedly increases
- HbA2 nl or increased slightly
Rx
- iron chelators
- BM transplantation
- hydroxyurea
14
Q
Beta-Thal minor
A
- asx usually w mild hypochromic microcytic anemia
- HbF & HbA2 are both incr
- Important to dx to avoid treating as iron def. anemia
15
Q
alpha-Thal
A
- silent carrier= 1 alpha-gene deleted
- alpha-Thal trait= 2 genes deleted
- SE Asian: alpha/alpha -/-, CIS
- Africa: alpha/- alpha/i, TRANS
- only SE Asian alpha-Thal can produce severely affected offsprings
16
Q
HbH & Hydrops Fetalis
A
- HbH=3 alpha-genes deleted
- HbH actually formed from tetramers of excess beta chains
- high affinity for O2 -> tissue hypoxia
- ppt inclusions in older RBC
- extravascular hemolysis
- moderate anemia
- Hydrops fetalis= 4 alpha-genes deleted
- lethal
17
Q
PNH
A
- x-linked mutation of PIGA
- Etiopath:
- PIGA is a GPI normally inhibiting complement;
- mutations lead to more complementation activation from proteins including CD55/DAF, C59, C8
- conferring advantage in pt w autoimmune disease
- Sx:
- intravascular hemolysis
- mild to mod anemia
- prothrombotic state
- Dx:
- Hemoglobinemia, hemoglobinuria & hemosiderinuria
- flow cytometry for CD55/DAF & CD59 (need GPI to link on membrane) on WBC
- Flaer test
- Assoc
- iron deficiency can be a problem
- aplastic anemia
- thrombosis; main cause of death (Pathoma)
- AML or Myelodysplastic syndrome (main lesion of PNH is a mutation in myeloid stem cell)
18
Q
Hemolytic anemias: extrinsic RBC abnormalities
A
Immune hemolytic anemias (IHA)
- cold IHA: IgM-mediated disease usually involves intravascular hemolysis
- warm IHA: IgG-mediated disease usually involves extravascular; results in spherocyted
- cold hemolysin IHA
- Dx: direct and indirect Coombs test
Nonimmune hemolytic anemias
19
Q
DAT vs IDAT
A
- DAT: admin. anti-IgG Ab to RBC -> agglutinate
- IDAT: admin. test RBC w Ab -> agglutinate
20
Q
Warm Ab IHA
A
- most common IHA (50 to 75%)
- 50% idiopathic
- 50% predisposing diseases: autoimmune (SLE), lymphoma, or drug reactions
- Drug induces auto-Ab, Ex. Methyldopa
- Ab binds to drug-membrane complex, Ex. penicillin
- IgG mosty (smaller)
21
Q
Cold Agglutinin (Cold Ab) hemolytic anemia
A
- IgM mostly (bigger)
- Acute self-limiting hemolysis: mycoplasma pneumonia, CMV, infectious mono, influenza, HIV
- Chronic hemolysis: idiopathic or lymphoma
22
Q
Hemolysis due to mechanical RBC damage
A
- cardiac valve prostheses
- micovascular obstruction: microangiopathic hemolytic anemia
- DIC, malignant HPT, Thrombotic Thrombocytopenic Purpura (TTP) and Hemolytic-Uremic Syndrome (HUS), SLE, disseminated cancer
23
Q
Pernicious anemia: Vit B12 deficiency
A
- B12 absorbed in duodenum
- Causes:
- impaired absorption: most common, pernicious anemia, malabsorption, bowel resection
- increased requirement (rare)
- decreased intake: vegans
- pancreatic insufficiency -> less protease to cleave B12-R binder complex (pathoma)
- Damage to terminal ileum due to Crohn disease or Diphyllobothrium latum (pathoma)
- Etiopath: Atrophic gastritis -> impaired IF production -> impaired B12 absorption ->-> megaloblastic anemia
- Sx: neurological deficits (75%)
- insidious onset -> severe anemia by time of presentation
- macrocytic anemia w hypersegmented neutrophils
- glossitis
- subacute combined degeneration of spinal cord -> due to build up of methylmalonic acid in spinal cord (Pathoma)
- Dx: methylmalonic aciduria & serum homocysteine
- Schilling test: inability to absorb oral dose of B12.
- Reticulocyte response: look for improvement after 5 d parenteral B12 injection.
- Serum anti-IF ab
- incr homocysteine
- incr methylmalonic acid
24
Q
A
Megaloblastic anemias
- Cause: B12 or folate deficiency
- Etiopath: pernicious anemia (IF), Crohn’s (distal ileum),
- deficiency results in inadequate DNA synthesis -> defective nuclear maturation w relatively normal RNA & protein synthesis -> nuclear/cytoplasmic asynchrony
- Dx:
- PB smear showing pancytopenia
- macrocytic anema (MCV > 100)
- decr reticulocytes
- enlarged hypersegmented neutrophils (>7 lobes)
- BM findings
- hypercellular but ineffective hematopoiesis
- large cells
- PB smear showing pancytopenia
25
Q
Folic acid deficiency
A
- Folate absorbed in jejunum
-
Sx: no neuro deficits
- glossitis
-
Dx:
- PB & BM both show megaloblastic anemia w macrocytic RBC and hypersegemented neutrophils
- serology shows incr homocysteine & nl methylmalonic acid
26
Q
A
Iron deficiency anemia
Iron transport
- plasma protein transferrin: 33%
- normal serum iron: 100 to 120 ug/100ml
- TIBC: 300 to 350 mg/ml
Lab Dx:
- CBC: decr. Hb, decr MCV, incr RDW
- Early stages of iron def. anemia = normocytic (Pathoma)
- PB: microcytic hypochromic anemia; severe cases -> poikilocytosis w pencil and target cells
- bigger central pallor;
- most common cause in US is chronic blood loss from carcinoma or gastrectomy; impaired absorption (dumping syndrome, parasites)
- Biochem: decr ferritin, decr transferrin sat, decr serum Fe, incr TIBC, incr FEP (free erythrocyte protoporphyrin)
- Depletion of BM stores: Prussian blue-
Other Dx
- Koilonychia due iron deficiency anemia
28
Q
A
Aplastic anemia
- damage to HSC
- Congenital: Fanconi’s anemia (rare)
- Acquired
- Idiopathic (unknown cause): 65%
- known causes: 35% of cases (see below)
- Seen in teens & elderly
Etiologies
- drugs or chemicals: alkylating agents, CAT, chloropromazine, phenytoin & radiation
- viral infections: hepatitis (non-A, B, C, D, G), CMV, EBV, HHV-1, 2
- autoimmune damage
Lab Dx:
- PB: pancytopenia, normocytic, normochromic, low reticulocytes count (RC)
- BM: hypocellular; fat takes over, required to rule out leukemias and myelodysplastic syndrome); dry tap so BM biopsy required and Spleen nl size
Sx: neutropenia -> infections; thrombocytopenia -> abnormal bleeding time
Assoc with leukemia & PNH ( small percentage)
48
Q
A
- CLL is most common adult leukemia (aka Small lymphocytic lymphoma)
- Sx: cytopenias, enlarged LN, liver or spleen
- Dx:
- PB: small, mature lymphocytes & smudge cells (2o to membrane fragility)
- high WBC count
- BM: interstitial nodules -> diffuse replacement
- Immunophenotype: CD19, CD5 & CD20 co-expression, CD23, CD43 +ve
- PB: small, mature lymphocytes & smudge cells (2o to membrane fragility)
- C&C:
- indolent and incurable
- complication:
- auto-immune hemolytic anemia
- transformations to more aggressive neoplasm w larger cells: prolymphocytic leukemia (20%) & DLBL (10%)
- hypogammaglobinemia -> most common cause of death in CLL due to infections (Pathoma)
- cause of death: pancytopenia -> infections and bleeding
51
Q
A
Burkitt Lymphoma
- aggressive B-cell lymphoma assoc w EBV
Clinical scenarios
- African (Endemic) Burkitt -> 100% EBV
- preferred sites: mandible, ovaries, kidneys, adrenal glands
- Sporadic Burkitt -> 15% EBV
- preferred site: ileocecal/abdomen -> obstruction
- HIV-assoc Burkitt -> 25% EBV
Morphology
- starry sky appearance from macrophages eating necrotic cell debris from all the cell proliferation.
- normal looking lymphocytes,
- Extranodal masses in form of neoplasm growing from mandible (right)
- t(8;14) -> overexpression of MYC
- B sx: fever, night sweats, weight loss
- Investigations: flow cytometry CD19+, CD20+, CD10+, and surface Ig+
C&C rapid growth but responsive to chemotherapy
52
Q
A
Hairy cell leukemia
Morphology
- Right: Acid Phosphatase (TRAP) stain showing reticulin
- Hairy cell in PB; fried egg in BM
- BM with fibrosis so dry tap
- Accumulates in red pulp of spleen -> sequestration -> Howell-Jolly bodies & beefy red appearance -> splenomegaly
- Dx
- Flow: CD20, CD25, CD11c, 103
- biopsy -> TRAP stain + (mostly for hairy cell leukemia)
- Sx
- Middle age males, pancytopenia due to being trapped in reticulin & splenomegaly
- Rarely LN enlargement; asx or indolent; anemia
54
Q
A
Multiple myeloma
- Left: BM w abnormal plasma cells, excess clock face, golgi bodies secreting a lot of Ig
- Right: Rouleaux formation due high production of Ig causing RBC to stick
- Germinal centre B-cells acquired mutation -> transformed -> go to sites such as BM to proliferate -> plasma cell neoplasm
- middle age men w bone pains
Etiopath
- malignant proliferation of plasma cells in BM
- high serum IL-6 (important GF for plasma cell)
Sx: CRAB=Calcemia, Renal failure (2o to hypercalcemia, BJ proteins, amyloid), Anemia, Bone lesions
- cytopenias due to BM replacement
- organomegaly late in disease (liver, spleen, LN, lungs)
- bacterial infections: 2o to neutropenia and hypogammaglobinemia (nl IgG low)
- Dx
- Serum analysis:
- hypercalcemia,
- M spike aka gamma Ig -> monoclonal plasma cells
- Urine analysis: light chains BJ proteins
- AL amyloidosis -> myeloma kidney -> renal failure (Pathoma)
- Serum analysis:
55
Q
A
Hodgkin’s lymphoma (HL)
- Biopsy of LN
- neoplastic Reed-Sternberg cells (altered germinal centre B-lymphocytes appearing as large B cell w multilobed nuclei) secreting cytokines drawing in reactive/inflammatory cells
- Less tumour cells (Reed-Steenberg cells), more inflammatory cells
- Owl eye cells -> inclusion-like
- Hodgkin lymphoma starts in single node and spread continuously (whereas non-Hodgkin spread is unpredictable)
- Best prognosis is Hodgkin; younger age group
- Stages: 1-4
- Stage I: single LN
- Stage II: multipe LN involved on same side of diaphragm
- Stage III: multiple LN involved on both sides of diaphragm
- stage IV: multiple/disseminated involvement
- Sx: Most lymphomas lead to hemolytic anemia
- painless rubbery LN enlargement
- pain in involved LN after drinking EtOH
- fever, night sweats, weight loss
- cutaneous anergy (itching)
- Dx: HL divided into Classical or Variant HL according to immunophenotype
- Classical: CD15+, CD30+, CD45-
- Variant: CD20+, CD45, CD 15-, CD30-
- Eosinophilia (Pathoma)
- 2 groups of HL Types:
- nodular sclerosis (most common)
- mixed cellularity,
- lymphocyte-rich,
- lymphocyte-depleted
- Variant: lymphocyte-predominant
- Nodular sclerosis HL
- mostly adolescents or young adults
- mediastinal involvement
- Stage I or II @ presentation (mediastinal +/- neck LN)
- Large nodules, at least partly surrounded by thick fibrous collagen bands -> fibrosis cuts nodules hence the name
- Presence of Lacunar R-S cell (type of Reed-Sternberg cell)
- Mixed cellularity HL
- diffuse nodal replacement, frequent RS cells, often EBV+
- young adults & adults >55 yo men
- systemic sx and advanced stage (ab involvement) at presentation
- assoc w eosinophilia (Pathoma)
- Lymphocyte depleted HL
- abundant RS cells that may be bizarre & very often EBV+, background of few lymphocytes and fibrosis
- elderly of HIV+ w systemic sx and advanced stage IV @ presentation.
- Variant HL
- large nodules (but no collagen band fibrosis)
- L&H or popcorn cell (a type of Reed-Sternberg)
- Young men < 35 yo
- cervical or axillary nodes
- indolent behaviour but tendency to recur
- <5% transform to a non-HL large B-cell lymphoma
- Rx & Prognosis:
- Radiation +/- multi-agent chemo depending on clinical stage.
- stage is the most important prognostic indicator
- 5YDFS
- Stage I & II=90%
- Stage IV=60 to 70%
- C&C: long term survivors get 2o cancers including AML, lung cancers.
56
Q
A
ALL
- 85% ALL cases are pre-cursor B-cell types -> Childhood
- 15% ALL cases are T-cell neoplasms presenting as mediastinal masses -> Adolescent males
- Left image: Marked incr in lymphoblasts; mutations in genes involved in differentiation (TF) married w complementary mutations in genes involved in proliferation (MYC-ABL)
- Right image: PAS stain to ddx ALL from AML. ALL will show clear (agranular) cytoplasm; no Auer rods,
- Cytogenetics: 90% of ALL have hyperdiploidy (favourable prognosis) or translocation
- Sx: Abrupt onset and severe (short history of sx)
- bleeding problems -> petechiae, bruising, epistaxis
- cytopenias (and their sequelae), bone pain
- generalised enlargement of LN, liver, spleen
- thymic enlargement (T-ALL)
- testicular enlargement (B-ALL)
- CNS involvement (B-ALL): headaches, blurred vision, vomiting
- Dx: tdt marker in nucleus (Pathoma)
- B-ALL surface markers: CD10, CD19, CD20
- T-ALL surface markers: CD2 to CD8 (Blasts do no express CD10)
- Rx: multi-agent chemotherapy w prophylactic chemo to scrotum and brain; Bone marrow transplant (BMT) for relapsed cases
- Prognostic factors: see image
Assoc diseases: Down syndrome after age of 5
57
Q
A
AML
- adults and old people (>60 yo)
- Sx: Acute onset (weeks-months), sx related to cytopenias
- Tissue involvement can be a feature of AML w monocytic differentiatiion.
- Ex. skin=funny rash;
- mucosal=gum swelling
- AML: FAB classification
- Degree of maturation of granulocytic lineage of AML (M0 to M3)
- Presence of additional lineages of blast cell (M4 to M7)
- Chromosomal translocations
- younger adults w de novo AML such as promylocytic leukemia: t(15:17) aka RXR mutation & AMLM3
- Complication: Auer rods & granules inducing DIC
- most translocations -> better prognosis except those having chr 11
- younger adults w de novo AML such as promylocytic leukemia: t(15:17) aka RXR mutation & AMLM3
- Deletions & monosomy on chr 5 & chr 7
- Precursor syndrome: older people w AML w myelodysplasia (MDS) or post-chemo/radiotherapy
- Etiopath:
- mutations similar to ALL
- alkylating agents or radiotheraphy resulting in myelodysplastic disorder which can progress to AML
- Sx: rapid onset of sx of cytopenias
- anemia
- neutropenia: fever, sepsis
- thrombocytopenia: spontaneous mucosal, skin, intracranial bleeds
- M4 & M5 complication: skin and mucosal manifestations -> skin rashes, bleeding from gums (acute monoblastic leukemia), monocytes
- extramedullary masses (uncommon)
- hepataosplenomegaly: mild, if present
- Lab Dx:
- PM smear showing circulating blasts
- occasionally, aleukemic leukemia
- MPO stain -> aggregates called Auer rods
- BM aspirate & biopsy (Gold standard) > 20% blasts in BM
- Flow cytometry: expression of myeloid markers
- Cytogenetics
- Rx and Prognosis
- In AML w t(15;17), the chimeric RARalphaPML -> block of differentiation -> so Trans-retinal to differentiate cells to neutrophils.
- most AML given combination chemo
- t(8;21) & inv 16 = better
- t(15;7) = intermediate
- del 5 or 7 = poor
- BMT for high risk
- C&C: Acute megarkyoblastic leukemia emergency due to risk of DIC (Pathoma)
60
Q
A
CML (type of CMP): specific features
- 100% of cases have t(9;22) ; Philadelphia chromosome acquired at stem cell stage.
- mainly granulocytic
- 25 to 60 yo men
- PB smear image:
- striking left shift of leukocytosis, mostly neutrophils, metamyelocytes, and myelocytes, and eosinophils and basophils (basophilia)
- sometimes thrombocytosis
- BM: mostly granulocyte precursors w incr megakaryoctyes
- Sx: Gradual onset
- tiredness, weakness, loss of weight and appetite
- Enlarging spleen can lead to ab discomfort
Dx (Pathoma)
- DDx w infection which also show incr granulocytes
- CML granulocytes are Leukocyte Alkaline Phosphatase (LAP) -ve, i.e. leukemoid reaction -ve
- CML assoc w incr basophils
- CML granuloctyes exhibit t(9,22)
Course & complications:
- Stable phase: 3 y w 50% progressing to accelerated
- Accelerated: incr blasts, BM fibrosis, thrombocytopenia, and incr. cytogenetic abnormalities -> transformation to acute leukemia
- Blast crisis: looks like acute leukemia, left shift to stem cell stage, then 75% myeloid and 25% lymphoid stages
Rx:
- Imantinib (Gleevec) slows down TK activity of BCR-ABL translocation
- IFn-alpha
- Hydroxyurea: gentle chemo
- BMT
61
Q
Myelofibrosis
A
Myelofibrosis
- Left image: BM showing extensive reticular fibrosis
- Dysplastic megakaryocytes in clusters
- Distended marrow sinusoids, frequently containng intravascular hematopoiesis.
- Right image: BM reticulin stain for collagen III
- incr thickening of reticulin fibres; dense network of fibres
- proliferation of fibroblasts & deposition of collage w/in BM
- Image below: leukoerythroblastosis
- Tear-drop shape of dacryocyte, characteristic of myelofibrosis.
- Primary Myelofibrosis (aka Myeloid metaplasia):
- type of myeloproliferative disorder.
- hyperproliferation of neoplastic myeloid progenitors that retain capacity for terminal differentiation.
- Leads to incr in one or more formed elements of PB
- MPL or JAK kinase mutations (1o myelofibrosis)
- A lot of megakaryocyte -> secrete PDGF -> fibroblasts laid down in BM
- Sx: anemia, splenomegaly (extramedular hematopoiesis), leukoerythroblastic smear
- Dx: Dry tap on BM aspirate
- Course & complications:
- incr risk of infection, thrombosis, bleeding hemorrhagic episodes
- hyperurecemia, and gout due to rapid cell turnover
62
Q
A
Infectious mono
Morphology
- Arrow is pointing to atypical large lymphocytes called Downey cells
- Enlarged reactive CD8 T lymphocytes with increased cytoplasmic: nucleus ratio. Arrow is pointing to a phenomenon called “Dutch/Ballerina Skirt”. Nucleus of Lymphocytes in basophilic and peripherally located.
Etiopath
EBV spread via saliva→ virus invades and replicates inside epithelial cells of nasopharynx→ immune system response via CD8+ cells → symptoms (48wks after infec)
Sx
- Fever
- lymphadenopathy (cervical, axillary and inguinal)
- sore throat
- hepatosplenomegaly (T cell hyperplasia)
- Splenomegaly -> periarterial lymphatic sheath (PALS); in white pulp (Pathoma)
Dx
- Serology: look for Ab against EBV/CMV,
-
Heterophile-positive (Monospot) test
- Monospot test positive in EBV and negative in CMV
- employs heterophile Ab ->Latex agglutination assay -> reactive to sheep and donkey sera)
- lymph node biopsy find hyperplasia of paracortex (immature + mature T cells).
C&C
- incr risk of splenic rupture -> avoid contact sports
- rash if exposed to penicillin
- dormancy of virus conferring increased risk of lymphoma
● Lymphocyte depleted hodgkin’s lymphoma
● Burkitt’s Lymphoma (NHL)
● Nasopharyngeal carcinoma
● Oral hairy leukopenia
