WBC Pathology

Question 1

Why are neonates prone to sepsis?

Answer 1

Defective B-cell response against polysaccharide agents and abnormal cytokine release by neutrophils and monocytes

*Neutrophils not accurate index of infection - band count used primarily

Question 2

At what hemoglobin level does EPO increase?

Answer 2

below 10 gm/dL

*increases logarithmically

Question 3

What is the composition of blood?

Answer 3

55% plasma

45% cellular components (RBC and buffy coat)

Question 4

What is the absolute criterion of malignancy?

Answer 4

Metastasis

Question 5

Where do MOST lymphocytes enter lymph nodes?

Answer 5

High endothelial venules (HEVs)

Question 6

What is the most common cancer of children?

Answer 6

ALL

• B-ALL peaks around age 3
• T-ALL peaks in adolescence

Question 7

ALL

Answer 7

abrupt onset - within days to weeks of first sx

sx related to depression of BM - fatigue due to anemia, fever secondary to neutropenia and bleeding due to thrombocytopenia

mass effects caused by neoplastic infiltration - bone pain, lymphadenopathy, hepatosplenomegaly, testicular enlargement, and mediastinal compression (T-ALL)

CNS manifestations - headache, vomiting, and nerve palsy

Question 8

Burkitt lymphoma

Answer 8

Germinal center B cell is origin
aggressive
extranodal masses in adults

Question 9

Diffuse large B-cell lymphoma

Answer 9

Germinal or post-germinal center B cell is origin
Adults
Aggressive, rapidly growing mass (70% nodal)
Waldeyer ring frequently involved
Extranodal sites common

Question 10

Extranodal marginal zone lymphoma

Answer 10

Memory B cell is origin

Arises in extranodal sites in adults with chronic inflammatory disease

Question 11

Follicular lymphoma

Answer 11

Germinal center B cell is origin
older adults
generalized lymphadenopathy and marrow involvement

Question 12

Hairy cell leukemia

Answer 12

Memory B cell is origin
older white males 
pancytopenia and splenomegaly
increased atypical mycobacterial infections
BM aspiration difficult = "dry tap"

Question 13

Mantle cell lymphoma

Answer 13

Naive B cell is origin
older males with disseminated disease
painless lymphadenopathy most common sx
other systems involved: BM, liver, spleen and GI

Question 14

Multiple myeloma

Answer 14

Post-germinal-center BM plasma cell is origin
Older adults with lytic bone disease
hyperCalcemia, Renal failure, Anemia and Bone lesions (CRAB)
recurrent bacterial infections due to abnormal Ig production
Bence-Jones proteins in urine and increased Igs in the blood

Question 15

CLL

Answer 15

Naive B cell or memory B cell is origin
Older adults with BM, lymph node, spleen or liver disease
Autoimmune hemolysis and thrombocytopenia

Question 16

Adult T-cell leukemia

Answer 16

T-helper cell is origin
HTLV-1 virus
cutaneous lesions, marrow involvement and hypercalcemia
may cause progressive demyelinating disease of CNS and spinal cord

Question 17

Peripheral T-cell lymphoma

Answer 17

T-helper or T-cytotoxic is origin
Older adults
lymphadenopathy common
occasionally eosinophilia, pruritis, fever and weight loss

Question 18

Anaplastic large-cell lymphoma (ALK positive)

Answer 18

T-cytotoxic cell is origin
children and young adults
lymph node and soft tissue disease

Question 19

Extranodal NK/T-cell lymphoma

Answer 19

NK cell (common) or T-cytotoxic (rare) origin
EBV associated
Adults
Destructive extranodal masses (nasopharyngeal)

Question 20

Mycosis fungoides/Sezary syndrome

Answer 20

T-helper origin
Adult
Cutaneous patches, plaques, nodules or generalized erythema
Sezary syndrome = exfoliative erythroderma

Question 21

Large granular lymphocytic leukemia

Answer 21

T-cytotoxic and NK cell origin
Adult
Splenomegaly, neutropenia, and anemia

Question 22

Solitary myeloma (plasmocytoma)

Answer 22

Solitary osseous plasmocytoma

inevitably progresses to multiple myeloma (within 10-20 years)

Question 23

MGUS and smoldering myeloma

Answer 23

precursors to multiple myeloma

Question 24

Lymphoplasmacytic lymphoma

Answer 24

Plasma cell is origin
Secretes IgM in amounts sufficient to cause hyperviscosity syndrome (Waldenstrom macroglobulinemia)
Waldenstrom leads to retinopathy, neurologic sx and spontaneous bleeding
Similar to CLL but NO bony lesions

Question 25

Hodgkin vs Non-hodgkin lymphoma

Answer 25

NHLs occur at extranodal sites and spread in unpredictable fashion *Waldeyer ring commonly involved* HLs occur at a single node or chain of nodes and spread to contiguous lymphoid tissue *characterized by Reed-Sternberg cells*

Question 26

AML

Answer 26

clinically similar to ALL fatigue due to anemia, fever due to neutropenia, and thrombocytopenia (petechiae, ecchymosis, mucosal hemorrhage and hematuria) increased opportunistic infections predominate skin infiltration

Question 27

Myelodysplasia

Answer 27

group of clonal stem cell disorders with ineffective hematopoiesis and high risk of transforming to AML key pathogenic feature is a mutated, constitutively-activated tyrosine kinase extramedullary hematopoiesis is common

Question 28

polycythemia vera

Answer 28

Uncommon Increased marrow production of RBC, granulocytes and platelets with low EPO levels plethora, cyanosis, intense pruritis, headache, HTN, and GI ulceration splenomegaly hyperviscosity, major bleeding and thrombic episodes

Question 29

Essential thrombocytosis

Answer 29

uncommon increased production of megakaryocytes with high platelet counts thrombotic complications common

Question 30

CML

Answer 30

fatigue, weakness, weight loss and anorexia splenomegaly due to extramedullary hematopoiesis possible hepatomegaly or lymphadenopathy leukocytosis and hypercellular BM

Question 31

Primary Myelofibrosis

Answer 31

Least common of myeloproliferative disorders adults megakaryopoiesis and granulopoiesis fibrosis obliterates marrow which leads to extramedullary hematopoiesis splenomegaly prominent

Question 32

Multifocal Langerhans cell histiocytosis (Letterer-Siwe disease)

Answer 32

most frequent before 2 y/o cutaneous lesions resembling a seborrheic erruption fever and frequent infections hematosplenoegaly, lymphadenopathy, pulmonary lesions and bone lesions

Question 33

Unifocal Langerhans cell histiocytosis

Answer 33

langerhans cells with mixed eosiophils, lymphocytes, plasma cells and neutrophils skeletal system in older children most common in calvarium ribs and femur

Question 34

Multifocal unisystem Langerhans cell histiocytosis

Answer 34

langerhans cells with mixed eosiophils, lymphocytes, plasma cells and neutrophils multiple erosive bony masses in young children *Hand-Schuller-Christian triad: calvarial bone defects, diabetes insipidus and exopthalmos*

Question 35

Pulmonary Langerhans cell histiocytosis

Answer 35

Presents as bilateral interstitial disease multiple fine nodules and cysts in middle and upper lungs *associated with cigarette smoking so typically adult disease* may regress with smoking cessation