Leukemia/Lymphoma Translocations & Immunophenotypes

Question 1

Acute Myeloid Leukemia (AML) - Genetics (2)

Answer 1

1. Normal cytogenetics (do more testing; FLT3-ITD = allograft)
   (+)CD-33, CD-34, CD-117
2. RUNX1-RUNX1T1 - t(8;21)
   (+) CD-13/33/34, HLA-DR

Question 2

Acute Promyelocytic Leukemia (PML) - Genetics

Answer 2

PML-RAR-α fusion - t(15:17)
(+)CD-13, CD-33, HLA-DR
(-)CD-34

Question 3

Chronic myelomonocytic leukemia (CMML) - Genetics

Answer 3

CBFB-MYH11 fusion – inv(16)
(+) CD-34/117 in blasts
(+) CD-13/33 in granulocytes
(+) CD-14/11b in monocytes

Question 4

B-type Acute Lymphoblastic Leukemia (B-ALL) - Genetics (3)

Answer 4

1. BCR-ABL1 fusion – t(9:22) -or- IKZF1 transcription factor mutation
   (+)CD-10, CD-19, Tdt
2. MLL rearranged – t(11;19)
   (+)CD-19, Tdt
3. TEL-AML1 or ETV-RUNX1 – t(12:21)
   (+)CD-34/10, Tdt
   (-)CD-20

Question 5

T-type Acute Lymphoblastic Leukemia (T-ALL) - Genetics

Answer 5

TCR-alpha;HOX11 – translocation to chr.14

(+)CD-3, CD-5, Tdt

Question 6

Hairy Cell Leukemia

Answer 6

BRAF V600F mutation

(+)CD-19,20,22,11c,25,103

Question 7

Chronic Myelogenous Leukemia (CML)

Answer 7

BCR-ABL fusion gene – t(9;22) or +Ph

Question 8

Mastocytosis

Answer 8

C-KIT mutation -or- PDFR-RA – t(F1-P1)
(+)CD-25, CD117: this is also known as c-KIT, which is the receptor for SCF, which stimulate mast cell growth and migration

Question 9

Polycythemia vera

Answer 9

JAK2-V617F mutation

Question 10

Essential Thrombocytopenia

Answer 10

JAK2 (50%) -or- Calreticulin (25%) mutation

Question 11

Primary myelofibrosis

Answer 11

JAK2 mutation (TPO receptor downstream signal) is constitutively turned on (50%)

Question 12

Myelodysplastic syndrome with isolated del(5q)

Answer 12

ONLY loss of large arm of chromosome 5 (karyotype will show this)

Question 13

Refractory anemia with excess blasts

Answer 13

RAEB-1 mutation (5-9% morphologic blast formation)
-or- RAEB-2 mutation (10-19% morphologic blast formation)
(+)CD34/117

Question 14

Chronic lymphocytic leukemia/lymphoma (CLL/SLL)

Answer 14

80% will show by FISH…

• 13q deletion (good prognosis)
• trisomy 12 (bad prog.)
• 17p (p53) deletion (bad prog.)
• 11q deletion (bad prog)
• (+)CD-20/23/5/52
• Light chain restricted (either kappa OR lambda)
• If ZAP-70 or CD-38 are shown the prognosis is bad (sign of somatic hypermutation)

Question 15

Mantle cell lymphoma

Answer 15

IgH-Cyclin D – t(11:14)

• (+)CD-20/5
• (-) CD-23
• Light chain restricted
• Staining with Ki67 is characteristic because it stains cells with rapid mitotic rate (marker for very fast growth!)

Question 16

Burkitt lymphoma

Answer 16

MYC oncogene to IgH (8:14), Kappa (8:2), or Lambda (8:22) light chain genes

• (+)CD19, 20, 22, 79
• Ki-67 positive

Question 17

MGUS/Smoldering lymphoma/Myeloma Bone Disease

Answer 17

IgH fusion protein seen in FISH (66%)

• IgH-FGFR3 (14:4)
• IgH-CMAF (14:16)
• IgH-MAFB (14:20)
• 17p deletion (p53) – not good if present, poor prognosis

(+)CD-38/138
(-)CD-19/20
Light Chain restricted

Question 18

Follicular Lymphoma

Answer 18

t(14:18) IgH-Bcl-2 (>85%)
(+)BCL-2 is most characteristic
(+)BCL-6, CD-19/20/10

Question 19

Diffuse large B-cell lymphoma

Answer 19

IgH-BCL fusion t(14:18) -or- BCL-6 fusion gene t(v:3)

(+)CD-19/20/10
(+)BCL-2/BCL-6

Question 20

Hodgkin’s Lymphoma (2)

Answer 20

Classic: (+) CD-30/15/Pax-5; (-)CD-20

Lymphocyte predominant: (+) CD-20/Pax-5; (-) CD-30/15