Clear cell sarcoma case report: complex karyotype including t(12;22) in primary and metastatic tumor.

Clear cell sarcoma (CCS) is a rare and aggressive tumor, arising mainly in the soft tissue of the extremities in young adults. A distinctive chromosomal translocation, t(12;22)(q13;q12), has been found in most reported cases. We performed cytogenetic analyses on a primary and subsequent metastatic CCS that contained the t(12;22), along with other complex karyotypic changes. G-banding chromosome analysis was supplemented by spectral karyotyping (SKY), a 24-color chromosome-paint FISH technique, thus allowing identification of three marker chromosomes, unbalanced translocations, and other complex abnormalities. Four of these involved additional copies and structural abnormalities of chromosome 8. Clarifying such secondary karyotypic changes in CCS may prove valuable to the understanding of tumor cell biology and clinical behavior.