Rare

Male

65

12/2020

24

7

5

64

Two sub-populations of blasts were detected. One (approximately 40% of total events) expressed CD45 (dim), CD19, CD34, CD79a, CD10 (heterogeneous), TdT, CD22 (~90%), CD81 (dim), CD33 (dim/subset), CD38 (dim), CD66c, CD58, and CD73. The second population (approximately 20% of total events) expressed CD45 (dim), CD19, CD10 (strong), TdT (dim), CD22 (~97%), CD38, CD81, CD58, and CD73.

B-lymphoblastic leukemia with t(9;22)(q34;q11.2) BCR-ABL1

B-lymphoblastic leukemia with t(9;22)(q34;q11.2) BCR-ABL1

Bone Marrow

48h

No

G-banding

46,XY,t(9;22)(q34;q11.2),der(16)t(1;16)(q12;q24)[5]/46,XY[15]

Metaphase FISH

FISH nuc ish(ABL1,BCR)x3(ABL1 con BCRx2)[118/200], performed on peripheral blood

Yes

The patient was treated with Dasatinib, Decadron, Allopurinol, Hydroxyurea, and intravenous hydration in the acute setting but his hospital course was complicated by an exacerbation of his pre-existing atrial fibrillation, two right middle cerebral artery infarctions, and a pulmonary embolus with DVTs of the bilateral lower extremities. The patient decompensated and subsequently passed away.

No

The chromosomal abnormality der(16)t(1;16) is rare in hematologic malignancies. The specific translocation seen in our patient had previously only been reported in two cases of acute myeloid leukemia, specifically a 9 year-old girl with Fanconi anemia and a 22 year-old male, and a similar translocation [der(16)t(1;16)(q12;q11.2)] has been reported in B-lymphoid blast crisis of chronic myeloid leukemia (Yanagiya et al., 2020; Huret, 2000). This abnormality has also previously been reported in solid tumors like Ewing sarcoma where it carries a poor prognosis (Hattinger et al., 1996; Hattinger et al., 2000). The patientu2019s der(16)t(1;16)(q12;q24) represents a novel genetic abnormality that has not previously been reported in de-novo B-ALL, and little is known about this abnormality in B-ALL and its implications in pathogenesis and prognosis.