2009.08.11 – Chronic Myelomonocytic Leukemia with der(9)t(1;9)(q11;q34) as a Sole Abnormality

Annals of Clinical & Laboratory Science 39:307-312 (2009)
© 2009 Association of Clinical Scientists

Chronic Myelomonocytic Leukemia with der(9)t(1;9)(q11;q34) as a Sole Abnormality

Borum Suh1, Tae Sung Park1,*, Jin Seok Kim2, Jaewoo Song1, Juwon Kim1, Jong-Ha Yoo1,3 and Jong Rak Choi1

1 Departments of Laboratory Medicine and 2 Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; 3 Department of Laboratory Medicine, National Health Insurance Corporation Ilsan Hospital, Goyang-si, Kyonggi-do, Korea

Address correspondence to: Jong Rak Choi, M.D., Ph.D., Department of Laboratory Medicine, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea; tel 822 2228 2445; fax 822 313 0956; e-mail cjr0606@yuhs.ac.

The chromosomal abnormality der(9)t(1;9)(q11;q34) is a rareoccurrence in patients with hematologic malignancies. As faras we know, only 3 cases of acute myeloid leukemia, 1 case ofpolycythemia vera, and 1 case of multiple myeloma with thisderivative chromosome have been reported in the literature.Here we report the first case of der(9)t(1;9)(q11;q34) in apatient with chronic myelomonocytic leukemia (CMML). A 45-yr-oldman was brought to our hospital for evaluation of pancytopeniaand monocytosis. The patient’s persistent monocytosisin peripheral blood and his bone marrow findings were consistentwith the diagnosis of CMML. Chromosome study results repeatedlyshowed 46,XY,der(9)t(1;9)(q11;q34). In addition, the BCR/ABLfluorescent in situ hybridization (FISH) pattern of the interphasecells was interpreted as: “nuc ish(ABL, BCR) x 2[292/300],”consistent with the normal signal patterns found in 97% of thenuclei examined. For further evaluation, multi-color FISH (mFISH)analysis was performed and it showed the distinct unbalancedderivative chromosome der(9)t(1;9)(q11;q34) in 5 metaphase cellsanalyzed. Not only does this show an extraordinary type of trisomy1q, but it reveals a rare recurrent case of der(9)t(1;9)(q11;q34)in patients with monocytic-lineage leukemia. Further studiesare needed to evaluate the prognosis, survival, and treatmentresponse of such patients with der(9)t(1;9)(q11;q34).

Keywords: der(9)t(1;9)(q11;q34), CMML, mFISH, monocytic-lineage leukemia