Cytogenetic and fluorescence in situ hybridization analyses of a microcystic adnexal carcinoma with del(6)(q23q25).

Cytogenetic analysis of a case of microcystic adnexal carcinoma (MAC) revealed three unrelated clones with the karyotypes: 46,XX,del(6)(q23q25)[17]/46,XX,1 approximately 2dmin[4]/46,XX,t(1;3) (p10;q10)[2]. Analysis of the 6q- by fluorescence in situ hybridization (FISH) showed that it had resulted from a long arm deletion. The finding of a clonal 6q deletion as the sole karyotypic change in a MAC is of special interest because we previously have identified 6q deletions in different types of malignant salivary gland tumors. This observation, together with the histopathologic similarities between salivary gland tumors and sweat gland tumors, further emphasize the histogenetic relationships between these tumor types.