WBC Lecture 2: BM, Non-Malignant WBC Disorders

Spicule

(BM eval) Relatively intact marrow consisting of hematopoietic and stromal cells (observed under low power -10x)

• x100 magnification

• Count 300-500 nucleated cells

• Determine M:E ratio

How to perform an aspirate differential (3)

1.5:1 - 3.3:1

Normal M:E ratio of BM

• Absent

• Decreased

• Adequate

• Moderately increased

• Markedly increased

BM iron is reported as… (5)

• 2-10/lpf

• Hypoplasia or poor quality aspirate

• Hyperplasia

(——) is the normal range of megakaryocytes in the BM, while a low amount would indicate (—2—) and a cluster would indicate (——)

• Assess peripheral blood dilution

• Find bony spicules and areas of clear cell morphology

• Fat:Marrow ratio (estimate cellularity)

• Search for tumor cells in clusters

• Examine/estimate megakaryocytes

With a bone marrow aspirate, what is observed at low power (10x)? (5)

• Observe myelocytic and erythrocytic maturation

• Distinguish abnormal distribution of cells or cell maturation stages

• Perform differential count on 300 to 1000 cells

• Compute myeloid-to-erythroid ratio

With a bone marrow aspirate, what is observed at high power (50x and 100x)? (4)

• 50% (1:1)

• 100 - age ± 10

• Increased, decreased, normal

BM cellularity in adults is approximately (——), but the general rule to estimate normal cellularity for a certain age is (——). Cellularity is reported as… (—3—)

Normal

Evaluate the BM cellularity

Hypercellular/increased

Evaluate the bone marrow cellularity

Hypocellular/decreased

Evaluate the bone marrow cellularity

• Pt history, age, sex, etc.

• Description of samples received

• PB: CBC, ESR, retic, manual diff, PBS

• BM diff

• Description of cellularity, M:E ratio

• Iron stores

• Description of histological sections

• Diagnostic conclusion

What is included in a bone marrow report? (8)

Spicule

The current field in a BM smear is a good example of a…

Plasma cells

Identify the cells shown in the BM aspirate

• Shift in neutrophils from marginal to circulatory pool

• Increase in BM production

• Release of neutrophils from storage to PB

• Seen in infections

Characteristics of pathological absolute neutrophilia (4)

• Infection

• Storage pool

• Neutrophilia and toxic changes

Left shift describes as increased number of immature cells as an indicator of (——) with increase in bands, metamyelocytes, and myelocytes. It involves an increase in release from (——) and is usually seen alongside (—2—)

• > 50×10³/µL

• Neutrophilia

• Marked left shift (band, meta, myelo)

Characteristics of leukemoid reaction (3)

• Severe/chronic infection (i.e., TB, pneumonia)

• Metabolic disease

• Inflammation

• Response to malignancy

Leukemoid reactions are mostly a result of… (4)

• LR: Normal count and morph

• CML: Elevated, maybe mixed granulation

Difference between leukemoid reactions and chronic myeloid leukemia regarding eosinophils and basophils

• LR: toxic gran and Dohle bodies

• CML: maybe psuedo-Pelger Huet

Difference between leukemoid reactions and chronic myeloid leukemia regarding neutrophil morphology

• LR: normal

• CML: Elevated early, decreased late

Difference between leukemoid reactions and chronic myeloid leukemia regarding platelet count

• LR: Normal

• CML: Possible giant, hypogranular, and/or bizarre forms

Difference between leukemoid reactions and chronic myeloid leukemia regarding platelet morphology

• LR: Elevated

• CML: Decreased

• (RI: 15-170)

Difference between leukemoid reactions and chronic myeloid leukemia regarding LAP score

• LR: Normal

• CML: Positive for t(9;22); BCR-ABL

Difference between leukemoid reactions and chronic myeloid leukemia regarding genetics

• Immature neutrophils

• nRBCs

• Dacrocytes

• Neutrophilia often (not always)

Leukoerythroblastic picture (4)

• Metastatic tumors

• Fibrosis

• Lymphoma

• Leukemia

• Primary myelofibrosis

Leukoerythroblastic reactions point to the possibility of a space-occupying lesion in the bone marrow, such as… (5)

• Hyposegmentation

• Hypersegmentation

• Pyknotic and necrobiotic forms

Qualitative (acquired) granulocyte disorders in the nucleus (3)

• Toxic granulation

• Degranulation

• Vacuolization (with/without engulfed matter)

• Dohle bodies

Qualitative (acquired) granulocyte disorders in the cytoplasm (4)

• Chronic infection

• Megaloblastic anemia

• Drugs

Hypersegmentation is usually seen in… (3)

• Myelodysplastic syndromes

• Asynchrony of nuclear maturation (→ clumped chromatin, no segmentation)

Hyposegmentation is usually seen in… (2)

Pyknotic

Dying cell with a very dark/dense nucleus; filaments still visible

Necrotic

Dead cell, no filaments

• Toxic granulation

• Dohle bodies

• Cytoplasmic vacuoles

Toxic changes in neutrophils include… (3)

• Inflammation

• Infection

• Administration of G-CSF

Toxic granulation is associated with… (3)

• Bacterial infection

• Sepsis

• Pregnancy

Dohle bodies are associated with… (3)

• Septicemia (or other infection)

• Autophagocytosis secondary to drug ingenstion

• Acute alcoholism

• storage artifact

Cytoplasmic vacuolization of neutrophils are associated with… (4)

• Neutrophils

• Ribosomal RNA

Dohle bodies are only seen in (——), and they are remnants of (——-)

Platelet satellitism

Identify what is happening in this picture

Yeast

Identify the inclusion in the WBC

Bacilli

Identify the inclusion in the WBC

Histoplasma capsulatum

Identify the inclusion in the WBC

Autosomal dominant

Inheritance pattern of Pelger Huet Anomaly

Heterozygous state

Identify the form of Pelger Huet anomaly according the the following characteristics:

• Bi-lobed nucleus

• Dense heterochromatin

• Incomplete nuclear segmentation

• Dumbbell or pince-nez morphology

Homozygous state

Identify the form of Pelger Huet anomaly according the the following characteristics:

• Nucleus is round or oval

• No segmentation

70-90%

In true Pelger-Huet Anomaly, (——) of neutrophils are affected

• Drugs

• HIV, TB, Mycoplasma pneumonia, severe bacterial infection

• Myelodysplastic syndromes, acute leukemia, chronic myeloproliferative disorders

What can cause pseudo-Pelger-Huet anomaly (8)

Autosomal recessive

Alder Reilly Anomaly inheritance pattern

Alder-Reilly Anomaly

Abnormally large metachromatic granules in the cytoplasm of granulocytes, monocytes, and lymphocytes; leukocyte function is unaffected

Mucopolysaccharides

Alder Reilly anomaly involves the incomplete degradation of (——) deposits in WBCs

Autosomal dominant

May Hegglin Anomaly inheritance pattern

• Giant, bizarre PLTs (maybe hypogran)

• Leukopenia w/ large basophilic inclusions

• Variable thrombocytopenia

• Usually asymptomatic or mild bleeding disorder

May Hegglin Anomaly characteristics (4)

Autosomal recessive

Chediak Higashi Syndrome inheritance pattern

Chediak Higashi Syndrome

Characterized by abnormal fusion of granules in most cells that contain granules (including hematopoietic cells); fused granules are large and mostly dysfunctional; disease manifestations can be found in hair, skin, adrenal/pituitary glands, and nerves

Dysfunctional phagocytosis and ineffective bacterial destruction

How does Chediak Higashi affect WBCs

Dense PLT granules → tendency to bleed

How does Chediak Higashi affect PLTs

• Albinism (affects melanocytes)

• Neurological complications through childhood (peripheral neuropathy)

Other effects of Chediak-Higashi (not found in blood) (2)

Rare X linked or Autosomal Recessive

Chronic granulomatous disease inheritance pattern

• NADPH oxidase

• Normal or with toxic changes

Chronic granulomatous disease involves the decreaed ability of phagocytes to produce (——) (kills microorganisms); neutrophil morphology is usually (——)

Granulomas

In chronic granulomatous disease, bacteria are not killed upon ingestion; instead, they are encased in (——) to keep them localized, but they may rupture

• Nitroblue tetrazolium (NBT) reduction test

• Flow cytometry

What can be used to diagnose chronic granulomatous disease (2)

• Nuclear contortion

• Inc. cytoplasmic volume

• Inc. # cytoplasmic granules

• Evidence of phagocytic activity (vacuoles, debris, irregular border)

(Qualitative Changes) Reactive changes during infection, recovery from BM aplasia or post GM-CSF include… (4)

Macrophages and monocytes in BM and spleen

Lysosomal storage diseases are enzyme deficiencies where phagocytized material accumulate in cells due to degredation. It is typically seen in…

Gaucher Disease

Most common lysosomal lipid storage disease; unmetabolized lipid accumulates in the macrophages throughout the body; BM contains macrophages that have abundant fibrillar blue gray cytoplasm with wrinkled apeparance

Niemann Pick Disease

Lipid buildup in macrophages; BM contains macrophages that contain foamy cytoplasm packed with lipid-filled lysosomes that appear as vacuoles after staining

Epstein Barr Virus (EBV)

Infectious mononucleosis is caused by the (——); this virus infects >90% of the world population, usually with young children

CD21

EBV preferentially infects B lymphocytes by attaching to (——) receptors

Heterophile antibodies

Infectious mononucleosis involves the production of (——) in serum, which reacts with RBCs from horse or sheep → principle of Mono test

• Reactive lymphs

• Elevated WBC (10-30×10⁹/L)

• Absolute lymphocytosis

• Wide variation in lymphocyte morph

Infectious mononucleosis PBS characteristics (4)