ASCP LYMPH NODE (benign)

The most common cause of specific benign lymphadenopathy (LAD)

% of pts who undergo lymph node bx in which a specific diagnosis cannot be determined

what feature in LAD strongly suggests malignancy

most common specific cause of LAD= infectious

approx 40-60% of pts undergoing lymph node biopsy, a specific diagnosis cannot be determined (presumed majority are viral (or other ) infectious

Persistence (ie several months) or progressive (despite tx) strongly suggests a malignancy

ASCP LYMPH NODE (benign)

Follicular hyperplasia-

general features, morphology, differential diagnosis

-FH: most common pattern of reactive LN, especially in children and adolescents; usually non-specific and does not suggest specific etiology.  Seen in early HIV infection; and in pts with RA or other autoimmune disease (ie SLE)

       -- FH in autoimmunity:  seen in 29-75% of RA pts; typically local (epitrochlear, preauricular) or more generalized; RA pts are at increased risk of lymphoma.  Morphology in RA- similar follicular morphology, but interfollicular areas usually contain sheets or increased numbers of polyclonal plasma cells and neutrophils (in sinuses)

-Morphology: enlarged LN's, cortex expanded by follicles with germinal centers, but relatively low density;  follicles of varied and irregular size and shape; mantle zones, starry sky pattern/tingible body macrophages and germinal center polarization;  Follicle centers BCL-2 negative.

[image]

-Differential diagnosis: 

(1) FL: particularly grades 2 and 3, which have prominent centroblasts, grading FL- most important to differentiate grd 1/2 (low grade) from grd 3 (high grade) for tx.  High density follicles, absence of polarization, BCL-2 overexpressed; t(14;18) +, and BCL-6 + cells escaping into parafollicular area= lymphoma

(2) Other NHL-B-cell lymphomas, including CLL/SLL- with vague nodular area, consisting of paraimmunoblasts= proliferation centers; and mantle cell lymphoma- consisting of only centrocytes NO centroblasts!

(3) Classical Hodgkin's lymphoma- particularly NS variant, with partial nodal involvement; have thickened capsule, bands of sclerosis, Reed-sternberg and Lacunar cells, CD30+, CD45-, mixed background infiltrate.  And NLPHL- nodules, expanded FDC meshwork, Popcorn cells- CD20+, CD30-, EMA+, rimmed/rosette of CD57+T cells

(4) For FH cases a/w RA- consider other autoimmune diseases, plasma cell variant of Castleman's, syphilis, and mets from neoplasms- esp SCC

ASCP LYMPH NODE (benign)

Follicular pattern-

Castleman's disease-

types, general features of each type, morphology and differential diagnoses

Aka- Angiofollicular Lymph node hyperplasia

Types:

(1) Hyaline vascular: most common type, accounting for >90% of cases of CD; broad age range (median 33), no sex predilection; usually unicentric/single large, round mass; mediastinum common location; usually Asx'c

   -morphology: regressed/atrophic follicles, with expanded mantle zone, in concentric rings (onion-skinning), GC's may resemble Hassal's corpuscles of the thymus; thickened bv's penetrate the GC--> "lollipop" sign; striking interfollicular vascularity; clusters of monocytoid lymphocytes in interfollicular area and absent sinuses (which is unusual for a benign dz)

[image]

(2) Plasma Cell Variant:  <10% of cases; usually symptomatic- fever, myalgia, anemia, thrombocytosis, leukocytosis, elevated ESR, polyclonal hypergamm, high serum IL-6; usually multicentric (groups or matted nodes); abdominal involvement common

    --Morphology: follicular hyperplasia, with sheets of interfollicular plasma cells; usually polyclonal pc's, but may by monotypic (commonly lambda)- the monotypic cases are more commonly a/w HIV

Differential diagnosis:

(1) HIV associated LAD- smaller mantle zones, less vascularity, more plasma cells

(2) Mantle cell lymphoma- fusion of adjacent mantles, absence of vascularity, Cyclin D1+

(3) Angioimmunoblastic T-cell lymphoma- clear cells with atypia; coexpression of CD10 on T-cells, and EBV+

(4) and rare, but in the differential d/t vascularity= Bacillary angiomatosis d/t Bartonella henselae- in immunosuppressed pt, proliferative vascular pattern, smudgy purple fibrillar areas

[image] Warthin starry +

[image]

ASCP LYMPH NODE (benign)

Follicular pattern

Busy nodes vs Hodgkin's lymphoma

(1) PGTC vs NLPHL

(2) FH vs CHL

(3) CHL vs granulomatous infl

PTGC vs what variant of FL

(1) PGTC vs NLPHL- Reactive follicules WITHIN nodules is seen only in PTGC, never in NLPHL.  Can see reactive follicles at periphery of nodules

(2) CHL vs FH- a florid follicular hyperplasia can mask interfollicular involvement by CHL, so look good in paracortex and stain is suspicious

(3) CHL vs granulomatous infl- RS cells can hide in background of granulomatous infiltrate; scan with CD30

Side note: PTGC can be similar in H&E morphology to floral variant of FL; floral FL will not have background FH as PTGC does

[image]= Floral var FL

ASCP LYMPH NODE (benign)

Follicular pattern

Syphilis LAD

-generalized LAD in pts with secondary syphilis

-Morphology: similar to RA + thickened fibrous capsule filled with lymphocytes and plasma cells; perivascular lymphoplasmacytic infiltrate

   + fibrosing endarteritis, periarterits, and venulitis

   + Sarcoidal-type granulomas and clusters of epithelioid histiocytes in interfollicular region

   - Warthin-starry +, esp in blood vessels and epithelioid histiocytes

[image]= thickened fibrous capsule, filled with lymphs and plasma cells

[image]= spirochetes within epithelioid histiocytes (silver stain)

ASCP LYMPH NODE (benign)

three patterns of AIDS-related LAD

(1) Follicular hyperplasia: "explosive" FH, "naked" gc's (due to very small mantle zones); follicle lysis and hemorrhage; monocytoid B cells in paracortex and sinuses

(2) Follicular involution: burnt out/regressed follicles with thin/absent mantle zones; patchy interfollicular plasmacytosis- with histiocytes, immunoblasts and vascular proliferation; capsular fibrosis (resembles Castleman's disease)

(3) Lymphocyte depletion: small lymph nodes (so typically only seen at autopsy/not biopsied); follicles absent, depletion of lymphocytes, histiocytes and erythrophagocytosis.  Look for opportunistic infections, Kaposi's sarcoma and lymphoma

[image]

ASCP LYMPH NODE (benign)

Sinusoidal pattern

Sinus Histiocytosis with massive lymphadenopathy

-common name, general features, morphology (buzz word), staining

aka Rosai-Dorfman disease

General- prominent massive (bilateral) LAD; a/w fever, leukocytosis and polyclonal hypergamm; mc in children (first 2 decades), but can occur at any age; commonly involves extranodal sites (esp lung).  Spont resolves in most, some persistent LAD

-etiology still unknown (HHV-6, EBV, immune defect?)

Morphology: marked fibrous thickening of capsule with pericapsular fibrosis; prominent dilatation of all sinuses - containing large histiocytes with abundant clear-foamy cytoplasm;

*Emperipolesis- presence of viable-appearing lymphocytes and other hematopoietic cells, within histiocyte cytoplasm* a Chx finding

-staining: histiocytes + for CD68, S-100 and PLAP; (-) for CD1a

[image]

ASCP LYMPH NODE (benign)

sinus pattern-

miscellaneous entities producing this pattern and morphologic features

(1) Langerhans cell histiocytosis- coffee bean appearance oof Langerhan cell nuclei.  Eosinophils prominent; Langerhans cells- S-100 negative, and CD1a positive

(2) Vascular malformation of sinuses (VTS)- can be confused with Kaposi's sarcoma; however, has bland lining cells, compared to malignant cells in KS; KS extends beyond sinues, VTS is confined to sinuses only

(3) Whipple disease- caused by the organism- Tropheryma whipplei. present with abdominal- small bowel mesentery or retroperitoneal LAD, as well as diarrhea; histology LN- lipogranulomatous infiltrate, with several large epithelioid histiocytes, containing PAS-positive granular cytoplasm/may see the bacilli with PAS

[image][image]

(4) Hemophagocytic syndrome (aka HLH)- associated with many disease, but commonly connected to T-cell lymphomas in adults and viral infections in children;  Will have digestion of all hematopoietic cells, particularly RBCs; and karyorrhectic debris; vs emperipoleisis- mostly ingestion of lymphocytes, without digestion

(5) Monocytoid B-cell hyperplasia- often has neutrophils admixed with monocytoid cells; need to rule out other features of toxoplasmosis

(6) Lymphoangiographic changes- uncommon today, a dx given frequently decades ago

ASCP LYMPH NODE (benign)

Diffuse pattern

Infectious mono

EBV; usually effects teenagers, young adults; fever pharyngitis, PB lymphocytosis, cervical and/or generalized LAD; monospot test + (heterophile antibodies).  With classical clinical picture and dx'c tests- should NOT perform LN bx. 

morphology: Incomplete effacement of nodal architecture (with reactive follicles, patent sinuses containing immunoblasts an/or monocytoid cells and a heterogeneous population of lymphocytes in paracortex.  Immunoblastic proliferation in paracortex; large T- and B-cells with R-S like morphology (activated lymphs); prominent post-capillary venules; may have foci of necrosis; PB with reactive lymphs (with skirts)

[image]

Differential diagnosis:

(1) CHL- has true R-S cells, CD30+/CD15+, CD45-

(2) Large cell lymphoma- show monoclonal b-cell population or abnormal T-cell immnuophenotype (by flow or IHC)

(3) Anaplastic large cell lymphoma- Always CD30+, EMA+, ALK-1 usually +; t(2;5) in most and EBV-

(4) other viral syndromes- CMV, HSV or zoster (esp if necrosis is present)

(5) Hypersensitivity reactions- look for eosinophils; medication history (particulary anticonvulsants, Phenytoin most commonly

ASCP LYMPH NODE (benign)

Mixed pattern

Dermatopathic lymphadenitis

Usually a/w a benign or malignant chronic dermatologic lesion (ie MF)

Morphology: Vaguely nodular, pale expansion of paracortex; Pale-staining areas consist of histiocytes (with pigment), interdigitating dendritic cells and Langerhans cells

[image]

ASCP LYMPH NODE (benign)

Mixed pattern

Toxoplasmic LAD

a common parasitic infection world-wide; ~50% of adults have AB's to Toxoplasma gondii; Most common presentation- localized asymptomatic LAD (in adults); predilection for cervical nodes; self-limited

- can be a problem in pregnant women or can become acutely disseminated in immunocompromised

Morphology: back ground FH; *Clusters of epithelioid histiocytes in paracortex, encircling and encroaching on GC's; focal distention of sinuses by proliferation of monocytoid B-cells (as well as neutrophils).  MNGC and eos- typically absent

-Toxox cysts are not id'd- even with immunostains

-Dx confirmed by serology

[image][image]

ASCP LYMPH NODE (benign)

Cat-scratch disease LAD

aka Necrotizing granulomatous lymphadenitis, caused by Bartonella henselae

-most common cause of chronic lymph node enlargement in children; commonly found in children with close contact w/ kitten or cat

-Usually unilateral, commonly involves axillary, epitrochlear, cervical or inguinal nodes

-self-limited dz, resolves spontaneously

Morphology: Early lesion- FH --> stellate/geographic necrotising granulomas; the suppurative granulomas are distinctive; *Warthin-starry stain +

[image][image][image]

ASCP LYMPH NODE (benign)

Mixed pattern

Kikuchi-Fujimoto Disease

aka Histiocytic necrotizing lymphadenitis

-effects young women, esp Asian descent

-Isolated LAD, usually cervical, and often PAINFUL; +fever/FUO, neutropenia, lymphocytosis

-self-limited, benign

-unknown cause: ?viral, autoimmune (?some a/w SLE)

Morphology: ** Be cautious not to over call this lymphoma!

-patchy areas of necrosis, with prominent karyorrhectic debris, within cortex and paracortex **karyorrhexis without PMNs + presence of crescentic histiocytes**

-typical absence of neutrophils, Large mononuclear cells at periphery of necrotic tissue; crescentic/moon-shaped nuclei of histiocytes; +plasmacytoid monocytes, BUT*absence of plasma cells!

[image]

[image]=crescentic histiocytes

-Three morphology types- Proliferative; necrotizing (most common) and Xanthomatous

-There are a lot of background T-cells and large histiogytes with necrosis- so DO NOT confuse with lymphoma (esp Hodgkins)

Differential Dx:

(1) SLE_ similar morphology, but with MANY plasma cells; +hematoxylin bodies, and more extensive necrosis

(2) Herpes Simlplex- extensive necrosis, viral inclusions; particularly want to rule out HSV if it looks like a Richter's transformation in CLL/SLL

(3) Lymphoma- NHL (esp TC/HR-LBCL); or Hodgkins

LYMPH NODE (benign)

-additional study

Lymphgranuloma venereum

-lymphogranuloma venereum lymphadenitis, caused by Chlamydia trachomatis, serovar L1-L3; -a rare STD

-After latent period, 7-12 days, develop genital skin lesion (shallow ulcer, heals without scarring) followed by lymph node enlargement (inguinal or deep pelvic)- which are initially firm and tender; --> matted, scarred, may cause chronic sinus tracts or may resolve

-Morphology: microabscesses, coalesce with a prominent granulomatous reaction, -->geographic necrosis and palisaded granulomas.  Intravacuolar C. trachomatis organisms can be seen within vacuolated histiocytes- stain with bacterial stain (B&B, warthin starry) or giemsa.  Scarring--> lymphangiectasia and fibrosis

[image][image]

LYMPH NODE (benign)

-additional study

Mucocutaneous Lymph Node Syndrome

aka Kawasaki disease! -an autoimmune disease of young children (<5yrs), a/w inflamed medium-sized vessels throughout the body

-typically follows a viral infection;- conjuntivae, skin and oral mucosa become red and inflamed with edema; +cervical LAD and high fever

-is a systemic vasculitis; Chx'c- "strawberry tongue"

-typically non-suppurative lymphadenitis

ASCP HEMATOLOGY

What is the formula for calculating corrected reticulocyte count (CRC)?  And what is it used for?

CRC= % retics x Hct/45

-the count is corrected for the degree of anemia;

-A true reticulocytosis (↑CRC)- indicates hemolysis (in the absence of known bleeding), rather than a production problem

[Absolute retic count= % retics x RBC count]

-additional screening tests that indicated hemolysis:

    -- ↑ LDH; ↓ haptoglobin; ↑ bilirubin

ASCP HEMATOLOGY

characteristics of intravascular vs extravascular hemolysis

Intravascular                           Extravascular

-Schistocytes                           -Microspherocytes

-↑↑↑ LDH                                  -↑ LDH

-↓↓↓ haptoglobin                       -↓ haptoglobin

-Free Hb in serum                     - ↑ indirect bilirubin

-↑ urine Hb                              - Do not get free urine Hb

                                               -- ↑ urine urobilinogen

-No splenomegaly                    -Splenomegaly (a   

                                               prominent chx'c

[image][image]

ASCP HEMATOLOGY

Spherocytes-

-what are the two main diseases assoc w/ spherocytes?

-general fx of each dz

Spherocytes- small round, lack central pallor

[image]

(1) Autoimmune hemolytic anemia- DAT + (direct antiglobulin test); usually microspherocytes (low MCV)

-far mor common than hereditary/congenital causes

(2) Hereditary spherocytosis- Nl MCV, ↑ MCHC; little to no anemia, and nl retic ct (~10%)

-autosomal dominant inheritance; more common in northern european descent; a/w chronic extravascular hemolysis--> gallstones, etc

-Defect most commonly in ankyrin (band 3, etc).

-the most common congenital hemolytic d/o in northern europeans, but still overall not that common

ASCP HEMATOLOGY

Elliptocytes-

causes of elliptocytes/ovalocytes

general info on congenital cause

Elliptocytes= red cells >2x as long as they are wide

Causes

B12, folate, or iron deficiency

Myelodysplasia, myelophthisis (fibrosis)

   -- these causes- typically have fewer peripheral elliptocytes than HE

-Hereditary Elliptocytosis (HE):

  -->25% elliptocytes

  --Types of HE- common type (africa), mild dz; Stomatocytic- Malyasia, P.vivax/malarial protection, mild;  Spherocytic- co-inherited HS and HE;

* Hereditary pyropoikilocytosis- presents in infants as severe dz --then by 1 yr of age, looks like other mild forms of HE

-Defect in spectrin α or β (also protein 4.1, etc)

ASCP HEMATOLOGY

Stomatocytes-

common causes

-describe the congenital dz assoc w/ stomatocytes

-and clinical management of the congenital dz

Stomatocytes- thus named d/t appear like a mouth

[image]

Causes

-Rh_null red cell phenotype

-Medications (esp phenothiazines)

-Alcohol

-Liver disease

-Hereditary Stomatocytosis:

  --d/t abnormal Na/K permeability

  --defective stomatin

  --* may commonly develop thrombosis after splenectomy, so for this disease, should avoid splenectomy as treatment at all costs

ASCP HEMATOLOGY

Heinz bodies/bite cells

- heinz bodies in red cells- are denatured, precipitated Hb

[image]

-stained with supravital stain (ie methylene blue)- shows the heinz bodies

Will form in unstable Hb, Hb H, Hb Barts

-Sulfhemoglobinemia

-**G6PD deficiency-  most commonly a/w ; X-linked recessive inheritance.  Causes acute intermittent hemolysis

-in reaction to certain drugs (most commonly antimalarial- ie chloroquine), infection and fava beans

-These patients will tend to oxidize Hb d/t ↓ (reduced form) glutathione concentrations d/t lack of production of NADPH.

-Fluorescent spot test- is a screening test that fluoresces NADPH

-Quantitative G6PD assay, is confirmatory- NADPH is read at a wavelength of 340 nm

-*can get a false negative test (screen or confirm) after hemolysis- b/c all the red cells are new/young and have more G6PD

ASCP HEMATOLOGY

Echinocytes

-common causes

-one inherited cause, and features of this disease

Echinocytes, aka dessicocytes, burr cells

Causes- artifact (common), uremia, burns

*Pyruvate kinase (PK) deficiency- AR inheritance; seen worldwide; causes a chronic hemolytic anemia.

-Pyruvate kinase is needed to make ATP, and deficiency impairs the Embden-Meyerhof pathway:

  -- ↓ATP/↓NAD--> bad ion pumps--> echinocytes and hemolysis; however, this also leads to ↑ 2,3 DPG- which ↑O₂-carrying capacity and thus acts as a compensatory mechanism.  Thus most pts are Asx'c

-Fluorescent spot test- screening, fluoresces NAD

-Quantitative PK assay- confirmatory, tests NAD

ASCP HEMATOLOGY

Acanthocytes- common causes

Acanthocytes, aka spur cells

[image]

Causes:

-Liver disease

-Abetalipoproteinemia: absent β lipoprotein; retinitis pigmentosa and ataxia

-McLeod phenoytpe= absence of Kell antigens (Kx phenotype, or weak Kell Ags

-Post-splenectomy

ASCP HEMATOLOGY

Analysis of alkaline and acid gel hemoglobin electrophoresis

Alkaline gel: from anode (+) to cathode (-)= AFSC, A2 comigrates with C

Acid gel: from anode (+) to cathode (-)= CSAF, A2 comigrates with A

[image]

ASCP HEMATOLOGY

Sickle Cell-

disease and trait, lab dx'c differences, what tests are used

-main chx'c of each: % of each Hb type, avg red cell lifespan of SS pt

Sickle cell disease (SS)

[image]

Sickle cell trait (SA):

-mostly asymptomatic- some isosthenuria= urine has same specific gravity as plasma(protein free), due to lack of ability to concentrate or dilute the urine; are more susceptible to frequent UTIs.  Also at high altitude--> may develop complications of sickling, ie splenic infarct; and have increased risk of medullary renal carcinoma

-Hg [ ]: 35-45% S, <2% F, 1-4% A2, 50-65% A

the Hg gel electrophoresis for SA pts looks like:

[image]

Screening tests for Hb S (cheaper and faster then Hb electrophoresis)

(1) Sickling test (Sickladex)- using metabisulfite (which will not lyse the cells).  If Hb S >10%, cells will sickle.  Examine the sample microscopically to look for sickling.  Will be + in SS, SA, SC, S-other, C_harlem, and Hb Barts

(2) Solubility test- uses dithionite.  Cause rbc lysis and polymerization of Hb S (if >10%); examined grossly in tube.  If you can see the lines thru the tube is (-), if not, is (+).  will be + in SS, SA, SC, S-other, C_harlem, Heinz body anemia, paraproteinemia

Ex [image]

Other hemoglobin states that interact with Hemoglobin S:

-HbF- ↓ severity

-α-thalassemia: ↓ severity, b/c the α gene selects for the normal β protein- thus less α will make less Hg S.  with normal alpha- SA pt makes 35-45% S; with one alpha gene deletion- makes 30-40%, with two alpha gene deletions- makes 25-35%

-β thalassemia: ↑ severity, such that AS pts look more like SS pts.

ASCP HEMATOLOGY

What Hemoglobins run with S on alkaline gel?

Hg D, Hg G (which will have a negative sickladex- screening test)

-Hb Lepore (however, this will be <15%)- so may confuse SA pts, but not SS pts, which will not have such low range.

[image]

ASCP HEMATOLOGY

Hg SC disease:

- what is the hemoglobin makeup of these pts, severity of disease and peripheral blood findings

Typically 50% S, 50% C

-intermediate severity: SS>SC>>SA

The elecrophoresis gels look like this:

[image]

The peripheral blood usually shows, many target cells, with few sickle forms:

[image]

ASCP HEMATOLOGY

Hemoglobin C disease and trait

-what hemoglobin run with C on alkaline gel?

What conditions would lead to target cells?

Hemoglobin C disease (CC)

[image]

Hemoglobin C trait (CA)

-40-50% C, 50-60% A

-mostly asymptomatic

-normal CBC; but still have target cells on PBsmear

Electrophoresis gels look like:

[image]

Hemoglobins that run/comigrate with C on alkaline gel:

-A2 which is <3.5% in nl pts; Hb E (thalassemic); Hb O (clinically normal)

Conditions that produced target cells (codocytes) on PB:

-hyperlipidemia

-liver disease

-splenectomy

-Hemoglobinopathy: Hb C, Hb E, Hb S

-Thalassemia

-Iron deficiency anemia

ASCP HEMATOLOGY

Hemoglobin E disease

Hemoglobin E dz (EE)

-World-wide is very common- particularly in malarial prevalent areas; and esp southeast asia

-A very common beta chain defect:

--Worldwide: S>E>C

--US: S>C>E

-produces mild anemia.  Hb E-  comigrates with C on alkaline gel, but is closer to  A on acid gel- and will have thalassemic like indices, and target cells on PB

[image]

ASCP HEMATOLOGY

Describe methemoglobin, causes, effect and treatment

Describe carboxyhemoglobin and effects

(1) Methemoglobin: aka Hi, hemiglobin

   --is normally formed Hg, with Iron in a different state=> Fe stays in ferric state (Fe³⁺) instead of ferrous (Fe²⁺).  And thus cannot bind oxygen

   --causes: (a) inherited- Hb M (M-Iwate; M-Saskatoon) or reductase deficiency; (b) acquired: Nitrites, quinones;  Most common- is du/t meds

   -->cyanosis with "chocolate-brown blood"

   --Co-oximeter can measure directly (only the co-oximeter can detect Hi (pulse-ox and ABG cannot)

   --Tx: methylene blue

(2) Carboxyhemoglobin: cannot bind oxygen

   --CO (carbon monoxide)- binds Hg with 200X the affinity of O₂ so no oxygen will bind in presence of ↑ CO

            ----Has an even greater affinity for Hb F (so babies/fetus more affected

   --Source- partial combustion of fossil fules (so often seen in situation where family brings heater indoors

       --- also made endogenously from breakdown of heme

   -- Cherry red color to all skin and organs

   --Half-life depends on atmospheric oxygen tension: avg is 6 hrs on RT, vs 1 hr on 100% O2, so tx is high O2

ASCP HEMATOLOGY

Thalassemias

- α thal: types, general features, electrophoretic properties

[what is Hb Constant spring]

-β thal: types, general fx

[other more rare forms of beta thal]

-compare CBC indices of alpha and beta

Thalassemia= decreased production of affected chain (and excess of normal chain)

(A) α thal: everyone has FOUR alpha genes (as opposed to 2 like most genes); varying clinical picture from silent carrier to in utero hydrops based on number of genes knocked out

   --in utero precipitation of γ-chain (=fetal β chain)--> γ₄ tetramers (=Hb Barts)--> hydrops fetalis

   --later: if ≤3 chains affected - precipitation of β₄ tetramers = Hb H  (both Hb Barts and Hb H are fast migrators - migrate faster than Hb A

   -- Still make NL % of HbA, HbF and HbA2

[image]

[image]

[Hb Constant spring= Hb CS; mutation in the stop codon for alpha gene -->abnormally long, fragile transcript and abn Hb; --> 4 bands on electrophoresis (extra band); underproduction of alpha chain--> thalassemia]

(B) β thal: by 6-9 months of life- show precipitated α₄tetramers;

   --produce- ↓ HbA; and ↑ HbF and HbA2

[image]

Other more rare forms of beta thal:

  --Hb Lepore: Fusion of δ and β genes--> makes a long fragile transcript; Abnormal Hb -- extra bands on electrophoresis; and underproduction of alpha chain-> an alpha thal picture

       ----*suspect this whenever S band <15% (comigrates with Hb S)

   --δβ thal- deletion of both delta and beta genes--> β thal picture with normal HbA2 but elevated Hb F

(C) CBC indices between alpha and beta:

•  Both have microcytosis, with beta being worse than alpha
• α thal: MCV 65-75
• β thal: MCV 55-65
• Erythrocytosis, with very high RBC count: > 5.5 x 10¹²
• DDx: with these indices- is iron deficiency anemia- which will have a much higher RDW than thal; and will have Nl HbA2 levels in iron def anemia

ASCP HEMATOLOGY

Antibody-mediated hemolytic anemias:

-Warm autoimmune: type of Ab, specificity; diagnosis, causes

-the cold reacting antibody syndromes (3)-describe and compare- Ab, specificity, clinical settings and sx's

The most common of the autoimmune hemolytic anemias- is Warm autoimmune HA (warm AIHA)

- Warm autoimmune hemolytic anemia- a warm-reacting (reacts at body temp), IgG; has broad anti-Rh specificity

    --on BB ab screen--> across the board/panel reactivity on every cell; *+DAT (coombs test)- IgG phase or IgG and C3;  on PB- polychromasia and microspherocytes

    --Causes: idiopathic (30%); or secondary to: lymphoma, medication, collagen vascular disease

-Cold reacting antibody syndromes:

• PNH (paroxysmal cold hemoglobinuria)- Ab=IgG (Donath-Landsteiner), spec for anti-P.
• clinical- in the setting of virus (transient), or syphillis; a/w biphasic hemolysin --> intravascular hemolysis; decreased LAP score, thrombosis, eventual aplastic anemia and/or AML
• a population of the red cells have mutation in PIG-A gene--> encodes GPI, a protein that functions to protect RBC from complement (thru CD55 and CD59), so the cells have ↑sensitivity to complement
• Diagnosis:  Sucrose hemolysis test= promotes activation of complement and PNH pts will hemolyze; and Acidified serum (Ham's) test= both of which are low sensitivity and no longer used
• Flow- abnormal cells are CD55 and CD59 negative; nl rbc have both; can flow for FLAER (fluorescent aerolysin) binds specifically to GPI
• Rare but specific- erythrocytes being ingested by neutrophils on PB
• hemolysis in tube after cooling (to 4 C) then rewarming to 37 C

[image] 

• Cold agglutinin disease: Ab- IgM, spec for Anti-i, I, H Ag's; clinically seems to follow or is a/w Mycoplasma (anti-I) and infectious mono (anti-i), both are transient Ab's.  A/w in vitro hemolysis only; generally clinically silent; +/-Raynaud's; agglutination on PB after cooled below 37C (RT included)[image]
• Cryoglobulinemia: IgM monoclonal + IgG polyclonal (mixed cryoglobulinemia); spec- for anti-IgG (=rheumatoid factor)
• type I- myeloma; type II- a/w lymphoma, SLE, HCV* (50-60% are due to HCV)
• clinically- a/w thrombotic microangiopathy--> MPGN and renal failure (can see fibrin thrombi in glomerular and capillaries of kidneys; skin lesions, multisystem organ failure
• Wispy clouds on PB= cryoglobulin

[image][image]

ASCP HEMATOLOGY

RBC production defects

-Differential diagnosis of aplastic anemia

-sideroblastic anemia: PB findings, iron studies, types/causes

-CDA- types

Differential diagnosis of aplastic anemia with a marrow looking completely absent

[image]

-Hairy cell leukemia

-hypoplastic AML or MDS

-PNH

-sideroblastic anemia

-serous atrophy of fat

-cytotoxic T-LGL

Siderblastic anemia: ringed siderblasts, coarse basophilic stippling (Pappenheimer bodies= mitochondria fill with iron)

[image]

Iron studies- ↑ iron, %sat and ferritin

-most commonly acquired- thru stem cell defect (MDS), meds (isoniazid, chemo), alcohol

    --far less commonly is inheritd- XLR, some pyridoxine (B6) responsive

Congenital dyserythropoeitic anemia: 3 types, all RARE

•   Type I- RARE, internuclear bridges
• [image]
• Type II= HEMPAS (Hereditary Erythrocyte Multinucleation; Positive Acidified Serum (ham's test- to heterologous serum only)
• [image]

ASCP HEMATOLOGY

Fanconi anemia- causes, manifestation, inheritance pattern

other causes of pure red cell aplasia

autosomal recessive inheritance; *Ashkenazi jews, esp from south africa

-d/t chromosomal breakage syndrome==>increased sensitivity to DNA cross-linking agents

-manifests with congenital anomalies, pure red cells aplasia (with macrocytic anemia and ↑ HbF); sometimes with thrombocytopenia at presentation; eventually progress to aplastic anemia, MDS or AML

Other causes of pure red cell aplasia:

• Acquired:
• Viral- Parvovirus, EBV, CMV, HHV-6, HIV
• Thymoma (spindle cell/medullary variant)
• Large granular lymphocytosis/leukemia
• EPO therapy
• Transient erythroblastopenia of childhood
• Inherited: fanconi anemia; Diamond-blackfan anemia

ASCP HEMATOLOGY

Neutropenia-

-causes of increased destruction and decreased production

-what is the most common cause of neutropenia?

the most common cause of neutropenia is medications

-Increased destruction:

• Medications:
• antibiotics (penicillins, chloramphenicol)
• anti-thyroidals (methimazole, propylthiouracil, carbimazole)
• anticonvulsants (valproate, carbamazepine)
• procainamide 
• Autoimmunity: SLE, and RA (Felty's syndrome-?LGL leukemia); in children the autoimmune cause is unknown
• splenomegaly
• infection:
• typhoid fever, brucellosis, tularemia
• overwhelming sepsis (neonates, elderly)

Decreased production:

• Medications (chemo)
• Large granular lymphocytosis (cytotoxic T type)
• Constitutional:
• cyclic neutropenia- ELA2-related
• Congenital (Kostmann)- ELA2-related
• Schwachman-Diamond syndrome

ASCP HEMATOLOGY

Thrombocytopenia

ASCP HEMATOPATHOLOGY

What neoplasm is identified in the pictures?

[image]

[image]

Chronic lymphocytic leukemia/Small lymphocytic lymphoma

-smooth round nuclei, "cracked earth" or "checkerboard" chromatin

-small lymphs; by definition, less than 10% prolymphs (larger with nucleoli)- make up the vaguely nodular "proliferation centers"

-≥5 x 10⁹/L (5000/μL)

- Immunoph: CD19, CD20(dim), CD5, CD23, dim light chain (usually kappa); neg for CD38

**subtyped into (a) Pre-germinal center: non-mutated IgVH, poorer prog, CD38+, ZAP70+; and (b) Post-germinal center: Hyper mutated IgVH, better prog, CD38-, ZAP70-

** if same cells, and monoclonal but less than 5000/μL= monoclonal B cell lymphocytosis

ASCP HEMATOPATHOLOGY

What is the most likely diagnosis of this lymphoma, and what IHC would confirm the dx?

[image]

[image]

Mantle cell lymphoma

*Bcl-1 (cyclin D1)- overexpressed in nucleus

An aggressive lymphoma, the strongest independent predictor of prognosis= mitotic rate

Molecular- t(11;14)(q13;q32)= IgH (14q32)-CCND1 (11q13)- FISH has the highest sensitivity for dx'ing

IHC- CD19, CD20 (bright), CD5+, bright sIg (L>K); nuclear Bcl-1+; neg CD23, CD11c

CAUTION- don't want to miss blastic transformation/blastic variant: Tdt-; diffuse proliferation of large "blasty" cells, wiht BCL-1 +, Tdt-

DDx: lymphoblastic lymphoma

MCL blastic[image]

ASCP HEMATOPATHOLOGY

What lymphoma is identfied by the images and description?

[image]

-residual follicles, with diffuse/interfollicular infiltration of intermediate sized cells

[image]+ monocytoid B cells, plasma cells (and maybe increased eosinophils)

ANSWER: Marginal zone lymphoma

-Maybe be Nodal, Extranodal (MALT), or splenic

-consists of a diffuse, sinusoidal or interfollicular infiltrate of B cells (intermediate in and variable is size) withe sheet of monocytoid B cells, plasma cells (+plasmacytoid lymphs) +/- Dutcher bodies; and residual reactive lymphoid follicles with infiltration of the marginal zone

-IHC: CD19+. CD20+, sIg+, CD11c+ (general B cell markers, no distinct or special idenifying markers, but some may show aberrant CD43 expression); plasma cells may show light chain restriction; CD103 and annexin A1 -neg

MALT lymphomas- typically develop in response ot chronic inflammation and are often a/w chronic bacterial infection of mucosal tissues:

    --- Chlamydia psittaci- ocular (lacrimal)

    --- Helicobacter pylori- gastric (Most common)

    --- Borrelia burdorferi- cutaneous

    --- Campylobacter jejuni- IPSID

Molecular abnormalities- site specific

    ---t(11;18)- stomach ,lung

    ---t(1;14)- ocular, parotid, skin, lung, small bowel

    ---t(3;14)- ocular, thyroid, skin

    --- +3 and +18 - all sites

Histology- in mucosal tissues-- have lymphoepithelial lesions[image]

Splenic MZL- involves white pulp; moderate cytoplasm, polar villi and nucleoli

[image]

ASCP HEMATOPATHOLOGY

What is the immunophenotype of the leukemic cell depicted?

[image]

ANSWER: the leukemia is hairy cell leukemia

IHC- express bright B cell markers (CD19, CD20, CD79a, CD11c)

     + CD22, CD103, CD25 and annexin A1

     + BCL-1 (don't confuse with MCL)

Cytochemical stain: is + for TRAP (tartrate resistant acid phosphatase)

[image]

No diagnostic molecular findings

ASCP HEMATOPATHOLOGY

List the types and histologic features, prognosis of the lymphoma in the picture

[image]

[image]- most are 30-40%+

ANSWER: Diffuse Large B cell lymphoma

• Types:
• Primary CNS: Perivascular tight cuffs; large cells (almost never see a low-grade lymphoma in the CNS); presents as supratentorial mass, mimics GBM; median age=60, excludes HIV-associated
• [image]
• Intravascular lymphoma: poor prognosis, large CD20+ cells retained within vessels only, with minimal infiltration of surrounding tissue; difficult to dx, no mass effect
• T-cell/Histiocyte rich B cell lymphoma: effaced node, background of small tcells and increased histiocytes, scattered large atypical B cells; CD21 meshwork absent
• main DDx- NLPHL- background of mostly small b cells and rosettes of T cells around LP cells; +CD21 "moth-eaten" follicular dendritic network
• Primary mediastinal lymphoma: young adult, F>M (2-3:1); majority oare CD30+; often have abundant sclerosis which can obscure the lg atypical cells and can push them together (can confuse with adenoca)

[image]

• Primary effusion lymphoma: HHV8+ (like kaposi's and multicentric castleman's); usually HIV+; effusions contain large cells with immunoblastic/plasmablastic/anaplastic fx and cytoplasmic vacuolization; neg for B and T cell markers as well as myeloid Ag's
• + for CD45, CD30, CD38, CD138 and EMA; +clonal Ig rearrangement
• Lymphomatoid granulomatosis: presents as systemic vasculitis, is a high-grade B cell lymphoma, with background dense infiltrate of non-neoplastic T cells, in vessel walls, commonly present in lung
• [image]

ASCP HEMATOPATHOLOGY

Describe types, immunophenotype, molecular abnormalities of the lymphoma depicted:

[image]

ANSWER: Burkitt lymphoma

Types:

   --Endemic (african)- usually/almost always jaw, EBV+

   --Sporadic (western)- abdominal, EBV+/-

   --(immunodef associated/ Burkitt-like

IHC: CD19+, CD20+, sIg+, CD10+, BCL6+

     ---Ki-67: + in >99% of cells

  -Neg for CD34, TdT; as well as BCL-2

Molecular: translocations of C-MYC (8q32):

   --most commonly- t(8;14)- c-myc, Ig HC

   --t(2;8); of t(8;22) on kappa/lambda light chains, res

Histology- on aspirate- medium sized cells, high N:C ratio, dark blue cytoplasm with vacuoles (=contain lipid).  On H&E- starry sky pattern with numerous mitoses and apoptotic bodies:

[image]

ASCP HEMATOPATHOLOGY

list and describe the 3 WHO categories of Acute lymphoblastic leukemia/lymphoblastic lymphoma (ALL/LBL)

General:

-ALL= PB>20%; BM>25%

-ALL is 80% B; LBL is 80% T

-T-LBL: =anterior mediastinal mass

-B-ALL: cytopenia, splenomegaly, bone pain

3 WHO categories:

(1) B-ALL/LBL, NOS- CD34+, CD99+, TdT+, HLA-DR+, CD19+, CD10+/-; (neg CD20), sIg-

    --30-50% aberrantly express myeloid markers (usually CD13 or CD33)- can confuse with mixed lineage

   --prognosis- related to initial white count, age (2-10=favorable); gender (females favorable); initial response to therapy- CD on d14 BM=favorable

[image]

(2) B-ALL/LBL w/ recurrent cytogenetic abnormalities:

-Important remember the poor prognositic markers:

    --t(9;22)(q34;q11)=BCR-ABL, m-bcr, 190kD (worst)

    --t(v;11q23)= MLL gene rearrangements (FLT3+)

    --hypodiploid (<46 chr)

    --t(1;19)= E2A-PBX1

Others: t(12;21), hyperdilpoid (>50 chr)= both good prog; and t(5;14)= IL3-IGH- usual (no prognostic signif)

(3) T-ALL/LBL: on PB cells look essentially the same as B-ALL; howeve, may have "hand-mirror" morphology- more specific for T

   --Immunoph: CD34+, CD99+, Tdt+, CD7+, cytoplasmic CD3+

         ---HLA-DR (-)

         ---CD4/CD8= +/+ or -/-

[image]

ASCP HEMATOPATHOLOGY

Diagnostic criteria, clinical findings, molecular abnormalities, IHC, and histologic findings for the disease depicted

[image]

[image]

ANSWER: Multiple myeloma

Criteria:

[image]

CRAB= HyperCalcemia, Renal impairment, Anemia, Bone lytic lesions

Specific plasma cell abnormalities on histology: Gaucher-like cells, flame cells, mott cells; d/t inclusions

[image]

  Gaucher-like       Mott cells               Flame cell

Immunophenotype:

-CD45 (veyr dim); CD38/CD138 +(bright); cytoplasmic kappa or lambda (restricted)

-CD56+/- (aberrant); CD19/CD20 (-)

-10-50% CD10+, EMA+, CD30+f

Paraprotein frequencies:

IgG (55%) > IgA > LC only > IgD, biclonal, IgE, IgM

Kappa > lambda

-with suppression of polyclonal background/hypogammaglob background

Genetics:

=most important prognostic indicator, and FISH is most helpful

 most common= 14q32 (IGH) abn, esp t(11;14)(q32;q32) -same as for MCL

others:

-shortest survival= t(4;14), t(14;16) or del(17p)

-intermediate survival= 13q14 deletions alone

-longest survival= no anomalies (nl cg) or ONLY t(11;14)

ASCP HEMATOPATHOLOGY

Name the T-cell lymphoma:

(A) HTLV-1 associated; CD2, CD3, CD5, CD4, CD25+; CD7-

(B) CD4+, loss of one or more of T cell Ag's- CD2, CD3, CD5 or  CD7; most common T cell lymphoma in western hemisphere

(C) EBV+ (in background B cells), abrupt onset; Coombs + (AIHA), +cold-agglutinins, ASMA, +RF; IHC- markers of follicular center cells- CD10, BCL6 and CXCL13 +)

(D) Large cells in PB, abundant cytoplasm, neutropenia, CD3+, CD8+, CD16+, clonal TCR+

(E) children, young adults; defined by ALK+, w/ t(2;5), CD30+, T Ag's +, EBV-

(F) Large cells in PB, fever, jaundice, neutropenia, splenomegaly; indolent; EBV-; CD2+, CD3-, CD8+/-, CD56+/-, CD57+/-; No clonal TCR

(A) Adult T Cell Lymphoma/Leukemia (ATLL or ATCL)- HTLV-1 in all cases; Japan, SE US, caribbean; lymphocytosis, skin rashk hypercalcemia, lytic bone lesions

   -CD2+, CD3+, CD5+, CD4+, CD25+; CD7- 

   -PB- flower cells- atypical folded nuclei

     [image]

(B) Peripheral T-cell Lymphoma, NOS: most common T cell lymphoma in western countries; MUST exclude other T cell lymphomas

  -composite morphology- small ot large cells; high endothelial venules, eosinophiles, histiocytes

  -CD4+; CD8-; loss of one or more T cell Ag's (CD2, 3, 5, or 7)

(C)  Angioimmunoblastic T cell Lymphoma (AITL): "follicular T cell lymphoma"- originates from the specialized T cells within the germinal centers; are EBV+ (in B cells, not the neoplastic T's); clinical- abrupt onset, fever, constitutional sx, Coombs+ AIHA, pleural effusion, rash; Cold agglutinins, +Rheum factor; polyclonal hypergammagobulinemia

  -CD4+, CD3+ and follicular markers- CD10, Bcl6, CXCL-13

  -prominent post-capillary venules, nodules of clear cells (around vessels

[image]

(D) T-Large granular lymphocyte leukemia (LGL): CD3+, CD8+, CD16+, CD5 bimodal; Large granular lymphs in periphery; assoc neutropenia; strong association with rheumatoid arthritis (?Felty's), +splenomegaly; usually indolent; some are aggressive (usually CD56+ in agg); +clonal TCR rearrangement

(E) Anaplastic Large cell Lymphoma: a variant presents in children and young adults; typical ALCL- CD30+, ALK-1+, +T-cell Ag's; nodal; CD45+, EBV neg. consists of large anaplastic cells

[image]

  --Molecular fx: 90% have TCR clonal rearrangement

      ---MC= t(2;5)(p23;q35)- NPM/ALK (ALK on chr 2p23)

translocation type--has specific ALK IHC expression:

[image]

(F) NK-cell Large granular lymphocyte leukemia (NK-LGL):  Fever, jaundice, splenomegaly, neutropenia; EBV (neg)- differentiates from aggressive NK cell leukemia); indolent; CD2+, CD3(-), CD8+/-, CD56 +/-, CD57 +/-; germline TCR (no clonal TCR rearrangement)

Criteria for T and NK cell LGL leukemia- b/c LGLs are usually present in periphery as reactive lymphs- leukemia must meet these criteria:

- unexplained cause (no virus, drug, etc)

- sustained (> 6months)

- increase in # (>2 x 10⁹/L) in LGLs

ASCP HEMATOPATHOLOGY

Myelodysplastic syndromes-

definition of cytopenia; define MDS/criteria; DDx;  cytogenetic abnormalities (low, intermediate and high risk)

-list types of MDS 

WHO 2008- define cytopenia=

• erythroid: Hb <10 g/L
• Neuts: <1500/dl (1.5 ANC)
• plts: <100,000

MDS defined as dysplasia and cytopenia

Criteria: -cytopenia with dysplasia

-if cytopenia without dysplasia- must have cytogenetic abnormality

--If have cytopenia without dysplasia or cytogenetic abn= "idiopathic cytopenia of undetermined significance"

-----Must R/o DDx: B12/folate deficiency, heavy metal tox (arsenic), EtOH, HIV, zinc deficiency, copper def, medication (mycophenolate, bactrim)

molecular: cytogenetics usually complex (>2) abn's

those that are isolated abnormalities- are usually monosomy 7, 7q-, 5q-, +8

CG:

  --low-risk: normal cg, or isolated 5q-, 20q-, -Y

  --intermediate risk: all those not low or high risk

  --high risk: complex abnormalities (>2); -7, 7q-

Morphology:

• dyserythropoiesis: macrocytosis, anisopoikilocytosis, basophilic stippling; in marrow- karyorrhexis, multinucleation, blebbing, bridges (in >5-10%), ringed sideroblasts
• dysgranulopoiesis: hypogranularity, hyposegmentation; ringed nucleus; in BM- abnormal granulation, megaloblastoid change
• dysmegakaryopoiesis: micromegs, mononuclear, pawnball

ASCP HEMATOPATHOLOGY

What is the syndrome name described below and a/w with the cell in the picture:

- elderly woman; thrombocytosis, macrocytic anemia, micromegakaryocytes, good prognosis

[image] 

=5q- syndrome 

pic=pawnball mega

ASCP HEMATOPATHOLOGY

MPN's-

Chronic myelogenous leukemia:

-PB findings, LAP score, CBC findings, BM findings, Molecular, clinical course

CML

-PB: leukemoid reaction- full spectrum with left-shift- PMNs, bands, metas (with myelocyte bulge on CBC diff)

    --PB smear has lots of myelocytes + eosinophils/basophils

-LAP score: Leukocyte alkaline phosphatase-each neut and band given a score of 0-4+ by intensity;  and 100 cells counted- so scores 0-400

   --leukemoid reactions and other MPNs have HI LAP score

   --CML and PNH- have LO LAP score

CML- has lots of myelocytes just like PB, also panmyelosis ad small megs (dwarf)

Cytogenetics: Philadelphia chromosome- t(9;22)(q34;q11) BCR/ABL- at the major breakpoint cluster==> p210 fusion protein- usual type/most common

     [μ-BCR--> p290 (minor breakpoint)--> CML with marked thrombocytosis and mature neuts

     [and m-BCR= p190 in CML with marked monocytosis AND in Ph+ALL]

-BCR-ABL fusion protein is present in all cell lines; NO Jak-2 mutation

Clinical progression: chronic phase--> accelerated phase (increased basophilia, thrombocytosis, leukocytosis); blasts >10% and CG progression--> blast phase (AML)- >20% blasts and Cg progression

ASCP HEMATOPATHOLOGY

MPN's-

Other than CML list the 3 remaining MPNs- with pathologic findings and the associated mutation (with all 3)

MPN's (other than CML)

(1) Polycythemia vera- hypercellular marrow with erythroid hyperplasia; abnl megas (very atypical); in proliferative phase- no stainable iron.  Spent phase- dx by the atypical megs

-some recurrent CG abnl- 20q-, +8, +9

[image][image]

(2) Essential thrombocythemia (ET)- clinically either bleeding or thrombosis; marrow- massive megas with staghorn nuclei; thrombocytosis (>450K); no stainable iron; ↑ # megs in clusters

[image][image]

(3) Primary myelofibrosis (PMF)- streaming marrow, aytpical hyperplastic megas; hematopoiesis in sinusoids; and extramdullary hematopoiesis--> leukoerythroblastic PB smear

[image] [image]

recurrent cg abn (>50%): del(20q), del(13q), +8, +9

THE MAJOR molecular abnormality in ALL 3 MPN's (excluding CML)= JAK2 (Janus kinase) mutation- most commonly= V617F (minor mutation- exon 12)

  --mutation present in >90% of PV, >50% of ET and PMF

  --other common mutation= MPL (W515L or W515K)- found in some cases of PMF and ET

Neither mutation is needed to dx these MPNs and are not specific for MPNs

ASCP HEMATOPATHOLOGY

AML-

What are the categories of AML in WHO 2008

List and describe the subtypes of AML, NOS

AML

WHO 2008 categories of AML:

(1) AML, NOS (subcategories= M0-2, M4-7)

(2) AML with myelodysplasia-related changes

(3) AML, therapy related

(4) AML with recurrent cytogenetic abnormalities

Subcategories of AML, NOS:

(1) FAB, M0: <3% of cells express MPO, SBB or NSE; designate myeloid by flow or EM only: CD34+, HLA-DR+, CD13+, CD33+, CD117+ (up to 1/3 are TdT+).  main DDx: ALL

[image]

(2) FAB M1: >3% of blasts +MPO, SBB or NSE; >90% blasts undifferentiated; flow: (same as M0)- CD34+, HLA-DR+, CD13+, CD33+, CD117+ (not TdT); Main DDx: ALL

[image]

(3) FAB, M2: (aka AML with maturation)- >10% beyond blast (promyelo/myelo); Flow: CD34+/-, CD15+, HLA-DR+, CD13+, CD33+, CD117+; main DDx: r/o t(8;21)- will have CD19+

[image]

-may have granules and auer rods (but still majority are blasts)

(4) FAB, M4: aka (AMML)- myelomonocytic leukemia- >20% monocytic; >20% myeloid; flow: dual populations- in myelo and mono gates; monos- CD11b (and CD14)

(5) FAB, M5: monocytic/monoblastic- >80% non-erythroid cells are monocytic

   --M5a= >80% monoblasts

   --M5b= <80% monoblasts (mostly promonocytes)

(6) FAB, M6: >50% erythroids in BM (erythroleukemia subtype= >20% myeloid vs pure erythroid leukemia- >80% are erythroid); many dysplastic, with cytoplasmic vacuoles.

Main DDx: r/o Vit B12/Folate def

[image]

(7) FAB M7: >50% of blasts are megakarycytic; flow: CD41, CD61+

Main DDx: in newborn- Transient myeloproliferative disorder (down syndrome newborns)

[image]

ASCP HEMATOPATHOLOGY

in AML with recurrent cytogenetic abnormalities- which abnormalities have a favorable prognosis?

Criteria to designate AML as with myelodysplasia-related changes.

The two main therapeutic agents a/w therapy-related AML

AML with recurrent cytogenetic abnormalities:

favorable prog:

--t(8;21)(q22;q22)- M2-like morphology; IHC- CD19+, young adult; =AML1 and ETO genes

--Inv(16) or t(16;16): M4 like morphology with prominent eosinophilia; IHC- CD11b, CD14, CD64, young adult. involves genes MYH11 (myosin) and CBFβ. (formerly M4eo)

--t(15;17)(q22;q12)- found in APML (formerly M3); promyelocytes; IHC- CD34-, HLA-DR-. present with DIC and will rapidly recompensate if treated with chemo prior to ATRA.  fusion of RARα and PML genes

     --granular variant: low blast count, present with pancytopenia; dark prominent granules, auer not present or difficult to find

     --microgranular variant: high blast count, no or few granules, more evident auer rods

OTHER recurrent cytogenetic abnormalities:

• t(9;11)(p22;q23)- M5-like morph; children; CD4+, CD14+, CD64+, CD11b+; less commonly other translocations involving MLL (11q23) gene; intermediate prog
• t(6;9)- with basophilia; children and adults; poor prog
• t(1;22)- M7-like; infants; intermediate
• inv(3) or t(3;3)- poor prog

criteria or AML with MDS rel change: must have dysplasia in >50% of cells in at least 2 cell lines; usually complex cg

two therapeutic agents in t-AML:

-Topoisomerase Inhibitors- related with MLL/RUNX1 anomalies

-Alkylating agents

-avg latency from tx to AML is 5 yrs.

ASCP HEMATOPATHOLOGY

May-Hegglin anomaly- PB findings; chromosomal abn; inheritance pattern

Giant platelets in a pt with thrombocytopenia is most commonly seen in what condition?

May-Hegglin anomaly:

-PB: giant platelets; thrombocytpenia, Döhle bodies (granular inclusions)

[image]-giant plt and dohle body in neut

-autosomal dominant inheritance; a/w chr 22q12-13 (MYH9 gene- myosin)

The most common disorder with giant platelets in thrombocytopenia= ITP (immune thrombocytopenic purpura)

ASCP HEMATOPATHOLOGY

Hemophagocytic syndrome

HLH

-clinical: fever, HSM, pancytopenia, LAD, rash

- hypofibrinogenemia (↓↓) and hypertriglyceridemia (3sd from norm)

-causes:

  --familial- a/w PFR1 and others

  --PID: Chediak-higashi, Duncan's, etc)

  --Post-infectious - EBV

  --a/w malignancy (esp T-cell lymphoma)