Comparative genomic hybridization identifies 17q11.2 approximately q12 duplication as an early event in cutaneous T-cell lymphomas.

Mycosis fungoides (MF) and Sézary syndrome (SS) are primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of extranodal non-Hodgkin lymphomas. In the three cases of MF and four of SS studied, comparative genomic hybridization detected chromosomal imbalances in all SS cases and in one MF case. In all five abnormal cases, the long arm of chromosome 17 was completely or partially duplicated; in three of these five cases, it was the sole genomic event. Notably, a minimal common duplicated region at 17q11.2 approximately q12, corresponded to the mapping of HER2/neu and STAT family genes. The only recurrent loss involved chromosome 10, with deletion of the entire long arm in one case and deletion of band 10q23 in another. Sporadic imbalances included gains at chromosome arms 1q, 2q, 7p, 7q, and 12p. Genomic duplication at 17q11.2 approximately q12 emerged as a primary karyotypic abnormality common to both MF and SS, which suggests that this is an early clonal event.