CHROMOSOMAL-ABNORMALITIES IN CUTANEOUS T-CELL LYMPHOMA AND IN ITS PREMALIGNANT CONDITIONS AS DETECTED BY G-BANDING AND INTERPHASE CYTOGENETIC METHODS

The etiology of cutaneous T-cell lymphomas (CTCL) is unknown, We studi ed the pattern of chromosomal abnormalities with G-banding and interph ase in sib hybridization methods in blood mononuclear cells in 17 pati ents representing the different phases of CTCL or the premalignant con dition, parapsoriasis en plaque, and in 10 control persons. We used bi otinylated centromere-specific probes with fluorescent detection (FISH ) for chromosomes 1, 11, 8, and 17 and similar, enzymatically detectab le, digoxigenin-labeled probes for chromosomes 1, 6, 12, 17, and 18. I n G-banding, all patients showed numerical and structural chromosome a berrations, Numerical aberrations of chromosomes 6, 13, 15, and 17, ma rker chromosomes, and structural aberrations of chromosomes 3, 9, and 13 were increased in mycosis fungoides (MF) compared with healthy cont rols, In four of five patients the detection of a chromosomal clone pr eceded relapse or progression of the disease. In FISH of interphase ce lls, the cells abnormal for chromosomes 8 or 11, and for all four chro mosomes collectively, were increased in MF and in Sezary Syndrome (SS) . FISH and G-banding methods agreed statistically significantly for th e detection of monosomy, Also, digoxigenin-labeled probes hybridized t o interphases or mitoses detected aberrations corresponding to those o bserved with G-banding, Thus, chromosomally abnormal cells can be foun d in the peripheral blood of both parapsoriasis en plaque and CTCL pat ients, They can be detected with interphase cytogenetical methods, whi ch obviates the need for dividing cells, often difficult to accomplish in CTCL.