CYTOGENETIC FINDINGS IN 21 MALIGNANT MELANOMAS

Cytogenetic analysis was performed on 21 tumor samples of malignant me lanoma to identify the presence of consistent chromosome abnormalities . Four cases had a normal karyotype, and 17 were cytogenetically abnor mal. Numerical chromosome alterations were observed in 15 tumors: 12 w ere hyperdiploid and three were hypodiploid. The most frequent losses consisted of chromosomes 5, 9, 17 and Y. The structural abnormalities were usually complex, consisting mainly of nonreciprocal translocation s and deletions affecting 1p, 1q, 3p, and 9p. This study adds further data to previously reported melanoma cases, confirming that chromosome s 1, 3, 6, and 9 are nonrandomly affected.