TRANSLOCATION-T(8-13)(P11-Q11-12) IN STEM-CELL LEUKEMIA LYMPHOMA OF T-CELL AND MYELOID LINEAGES/

An unusual hematologic neoplasia has been described recently in which the predominant clinical features include T-cell lymphoma, myeloid hyp erplasia, and eosinophilia. The multilineage involvement in this disor der suggests transformation of a primitive stem cell. Abnormal karyoty pes have been described in three such cases, including one case with t (8;13)(p11.2;q12) and a second case with t(8;13)(p23;q14). We report t ranslocation of chromosomes 8 and 13 in lymph node karyotypes from two patients with this syndrome. Fluorescence in situ hybridization confi rmed an identical translocation, t(8;13)(p11;q11-12), in lymphoma cell s from each patient. The translocation breakpoints are of particular i nterest because the FLT3 receptor tyrosine kinase gene has been mapped to 13q12. FLT3 is expressed highly in hematopoietic progenitor cells and in myeloid and lymphoid acute leukemias. (C) 1995 Wiley-Liss, Inc.