Alveolar soft-part sarcoma: further evidence by FISH for the involvement of chromosome band 17q25.

A cytogenetic study of an alveolar soft-part sarcoma, a rare tumor of probably myogenic origin, demonstrated a t(X;17)(p11;q25) as the sole chromosomal abnormality. Dual- and triple-color fluorescence in situ hybridization, performed on metaphase and interphase cells, confirmed the translocation between chromosomes X and 17 and demonstrated that this translocation resulted in loss of 17q25. Involvement of 17q25 has been described in four previously published cases of alveolar soft-part sarcoma, but without further characterization. Compared to our karyotype, it seems that the derivative chromosome 17 observed in the reported cases could also be the result of a t(X;17) with possible loss of the 17q25 band. If so, a 17q25 deletion and/or chromosome rearrangement between Xp and 17q leading either to a gene fusion or gene disruption could play an important role in the pathogenesis of alveolar soft-part sarcoma.