Leukemia

Question 1

Acute Lymphoblastic Leukemia/Lymphoma (ALL)

Answer 1

• under 15yo
• Down syndrome
• Tdt+ (pre-B/T-cells)
• Tx responsive
• CNS and teste prophylaxis (untreated 80% get brain lymphoma)
• t(12;21) = good prognosis

T-ALL - CD2-CD8; thymic mass (SVC-like syndrome)
B-ALL - CD10+, CD19, CD20

Question 2

Small Lymphocytic Lymphoma (SLL)/ Chronic Lymphocytic Leukemia (CLL)

Answer 2

• over 60yo (most common adult leukemia)
• CD20+, CD5+, CD23+ naive B-cell neoplasm
• Often asymptomatic, slow progression
• Smudge cells
• Poor/lack of Ab (causes autoimmune hemolytic anemia or hypogammaglobinemia)

Question 3

Hairy cell Leukemia

Answer 3

• mature B-cell tumor in elderly
• Filamentous, hair-like projections
• Marrow fibrosis (dry tap)
• Tartrate-resistant acid phosphatase (TRAP) +ve stain
• Splenomegaly (red-pulp); absent LAD

Rx: cladribine, pentostatin

Question 4

Acute myelogenous leukemia (AML)

Answer 4

• over 65
• HIGH peripheral myeloblasts (monoblasts, megakaryoblasts lack MPO)
• Risk: Myeloproliferative, myelodysplastic, alkylating chemo, radiation
• Down syndrome

M3 AML: t(15:17) - PML-RAR(alpha) - Rx. all-trans retinoic acid (vit A) –> myeloblast differentiation

• DIC
• MPO crystalization –> Auer rods (peroxidase +ve)

Question 5

Chronic myelogenous leukemia (CML)

Answer 5

• 45-85yo
• t(9;22) = BCR-ABL = Philadelphia chromosome (increased tyrosine kinase activity)
• high neutrophils, metamyelocytes, BASOPHILS
• may become AML or ALL (“blast crisis”)
• very low LAP

Rx: imatinib