WBC Disorders

Question 1

Leukemoid reaction

Answer 1

• 25-30k WBCs

* Exaggerated response after infection or trauma

Question 2

Leukoerythroblastosis

Answer 2

• Immature WBCs and nucleated RBCs in peripheral blood

* Severe hemolytic anemia, abnormal bone marrow, massive trauma, Paget disease of bone, extramedullary hematopoiesis

Question 3

Neutrophilic leukocytosis

Answer 3

• Neutrophils >7.5k

* Infection, inflammation w/ necrosis, drugs

Question 4

Neuropenia

Answer 4

• Neutrophils

Question 5

Eosinophilia

Answer 5

• Eosinophils >400
• Type 1 hypersensitivity rxn, helminth infection, Churg-Strauss, Addison disease (eosinophils not sequestered in lymph nodes)

Question 6

Job syndrome

Answer 6

• STAT 3 mutation
• Abnormal neutrophil and monocyte chemotaxis
• “Cold” abscesses (lack of inflammatory response)

Question 7

Basophilia

Answer 7

• Basophils >110

* Myoproliferative disorders

Question 8

Lymphocytosis

Answer 8

• Lymphocytes >5000

* Infection, drugs, neoplasia, Graves disease (autoimmune thyroid disease)

Question 9

Mononucleosis

Answer 9

• Epstein-Barr virus
• Virus attaches to B cells and remains dormant there
• B cells are stimulated, release IgM
• Exudative tonsillitis, hepatosplenomegaly, lymphadenopathy
• Rarer findings: encdphalitis, pancreatitis, Guillain-Barré (peripheral nerve dmg), CN palsies, myositis
• Lymphocytes >20% of WBCs
• Heterophil Ab test, VCA + EA + EBNA Ab tests

Question 10

Monocytosis

Answer 10

• Monocytes >800

* Chronic inflammation, autoimmune disease, malignancy

Question 11

Polycythemia vera

Answer 11

• JAK2 mutation on chromosome 9
• Increased production of RBCs, granulocytes (neutrophils, eosinophils, basophils), mast cells, and platelets
• Hepatosplenomegaly, ruddy face, thromboses, CNS Sx, itchiness after bathing from mast cells, gout
• Increased RBCs, RBC mass, plasma vol
• Later stages: fibrotic marrow
• Treat with hydroxyurea

Question 12

Chronic myelogenous leukemia

Answer 12

• Middle-aged adults
• Risk factor: radiation
• Philadelphia chromosome: t(9;22) translocation leads to BCR-ABL fusion gene
• High WBCs, normocytic or macrocytic anemia, myeloid hyperplasia with few myeloblasts, decreased LAP
• Blast crisis: 5 yrs in, increased myeloblasts
• Treat with imatinib

Question 13

Myelofibrosis with myeloid metaplasia

Answer 13

• Adults >50 y/o
• JAK2 mutation
• Ineffective erythropoiesis in marrow w/ fibrosis; extramedullary hematopoiesis
• Massive splenomegaly, portal HTN, splenic infarct w/ L pleural effusion
• Normocytic anemia w/ teardrop cells, weird platelets
• Treat with hydroxyurea, interferon alpha

Question 14

Essential thromocythemia

Answer 14

• JAK2 mutation
• Excess, defective platelets
• GI bleeding, thrombosis, splenomegaly
• Thrombocytosis, basophilia, hypercellular marrow, weird megakaryocytes
• Treat with hydroxyurea

Question 15

Myelodysplastic syndromes

Answer 15

• Men 50-80 y/o
• Pancytopenia, normocytic to macrocytic or dimorphic anemias, ringed sideroblasts
• Often progresses to AML

Question 16

Acute myeloblastic leukemia

Answer 16

• Adults 30-60 y/o
• Risk factors: Down, Turner, Klinefelter syndromes; benzene and alkylating agents; t(8;21) translocation
• Constitutional Sx, hepatosplenomegaly, generalized lymphadenopathy; gum infiltration in acute monocytic leukemia
• Normocytic anemia, thrombocytopenia, leukocytosis; Auer rods in myeloblasts
• DIC common

Question 17

Acute lymphoblastic leukemia

Answer 17

• Common in children
• Risk factors: anticancer agents, Hodgkin lymphoma, multiple myeloma, benzene, radiation
• Mostly pre-B cell type
• Tests: CALLA, TdT
• t(12;21) translocation = good prognosis
• High WBCs, normocytic anemia, thrombocytopenia, bone marrow replaced by lymphoblasts
• Bad prognosis

Question 18

Adult T-cell leukemia

Answer 18

• Associated w/ HTLV-1 virus
• Activation of TAX inhibits p53; T cells proliferate
• Skin infiltration, lytic bone lesions
• Lymphoblasts positive for CD4, negative for TdT
• Normocytic anemia, thrombocytopenia, bone marrow replaced by CD4 lymphoblasts

Question 19

Chronic lymphocytic leukemia

Answer 19

• Adults >60 y/o
• Neoplastic disorder of virgin B cells (can’t differentiate into plasma cells)
• Immune hemolytic anemia
• High WBCs, few lymphoblasts, neutropenia, normocytic anemia, thrombocytopenia, bone marrow replaced by B cell lymphoblasts
• “Smudge” cells (fragile leukemic cells)
• Hypogammaglobulinemia

Question 20

Hairy cell leukemia

Answer 20

• Men 40-60 y/o
• B-cell leukemia; overexpression of cyclin D1
• Splenomegaly, autoimmune vasculitis/arthritis
• Pancytopenia, reticulin fibers in marrow, positive TRAP stain
• Leukemic cells with hair-like projections
• Treat with purine analog