WBC Pathology Flashcards
Why are neonates prone to sepsis?
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
At what hemoglobin level does EPO increase?
below 10 gm/dL
*increases logarithmically
What is the composition of blood?
55% plasma
45% cellular components (RBC and buffy coat)
What is the absolute criterion of malignancy?
Metastasis
Where do MOST lymphocytes enter lymph nodes?
High endothelial venules (HEVs)
What is the most common cancer of children?
ALL
- B-ALL peaks around age 3
- T-ALL peaks in adolescence
ALL
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
Burkitt lymphoma
Germinal center B cell is origin
aggressive
extranodal masses in adults
Diffuse large B-cell lymphoma
Germinal or post-germinal center B cell is origin
Adults
Aggressive, rapidly growing mass (70% nodal)
Waldeyer ring frequently involved
Extranodal sites common
Extranodal marginal zone lymphoma
Memory B cell is origin
Arises in extranodal sites in adults with chronic inflammatory disease
Follicular lymphoma
Germinal center B cell is origin
older adults
generalized lymphadenopathy and marrow involvement
Hairy cell leukemia
Memory B cell is origin older white males pancytopenia and splenomegaly increased atypical mycobacterial infections BM aspiration difficult = "dry tap"
Mantle cell lymphoma
Naive B cell is origin
older males with disseminated disease
painless lymphadenopathy most common sx
other systems involved: BM, liver, spleen and GI
Multiple myeloma
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
CLL
Naive B cell or memory B cell is origin
Older adults with BM, lymph node, spleen or liver disease
Autoimmune hemolysis and thrombocytopenia
Adult T-cell leukemia
T-helper cell is origin
HTLV-1 virus
cutaneous lesions, marrow involvement and hypercalcemia
may cause progressive demyelinating disease of CNS and spinal cord
Peripheral T-cell lymphoma
T-helper or T-cytotoxic is origin
Older adults
lymphadenopathy common
occasionally eosinophilia, pruritis, fever and weight loss
Anaplastic large-cell lymphoma (ALK positive)
T-cytotoxic cell is origin
children and young adults
lymph node and soft tissue disease
Extranodal NK/T-cell lymphoma
NK cell (common) or T-cytotoxic (rare) origin
EBV associated
Adults
Destructive extranodal masses (nasopharyngeal)
Mycosis fungoides/Sezary syndrome
T-helper origin
Adult
Cutaneous patches, plaques, nodules or generalized erythema
Sezary syndrome = exfoliative erythroderma
Large granular lymphocytic leukemia
T-cytotoxic and NK cell origin
Adult
Splenomegaly, neutropenia, and anemia
Solitary myeloma (plasmocytoma)
Solitary osseous plasmocytoma
inevitably progresses to multiple myeloma (within 10-20 years)
MGUS and smoldering myeloma
precursors to multiple myeloma
Lymphoplasmacytic lymphoma
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
Hodgkin vs Non-hodgkin lymphoma
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
AML
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
Myelodysplasia
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
polycythemia vera
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
Essential thrombocytosis
uncommon
increased production of megakaryocytes with high platelet counts
thrombotic complications common
CML
fatigue, weakness, weight loss and anorexia
splenomegaly due to extramedullary hematopoiesis
possible hepatomegaly or lymphadenopathy
leukocytosis and hypercellular BM
Primary Myelofibrosis
Least common of myeloproliferative disorders
adults
megakaryopoiesis and granulopoiesis
fibrosis obliterates marrow which leads to extramedullary hematopoiesis
splenomegaly prominent
Multifocal Langerhans cell histiocytosis (Letterer-Siwe disease)
most frequent before 2 y/o
cutaneous lesions resembling a seborrheic erruption
fever and frequent infections
hematosplenoegaly, lymphadenopathy, pulmonary lesions and bone lesions
Unifocal Langerhans cell histiocytosis
langerhans cells with mixed eosiophils, lymphocytes, plasma cells and neutrophils
skeletal system in older children
most common in calvarium ribs and femur
Multifocal unisystem Langerhans cell histiocytosis
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
Pulmonary Langerhans cell histiocytosis
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
