Unbalanced Chromosomal Rearrangements in a Metastasizing Salivary Gland Tumor with Benign Histology

Benign metastasizing pleomorphic adenoma (BMPA) is a rare tumor of the salivary glands. Despite benign histopathologic features, it can metastasize and is sometimes lethal. No chromosomal data have been reported for this tumor type. We have by chromosome banding and fluorescence in situ hybridization analysis examined the short-term cultures of three skeletal metastases from a BMPA and identified two related hypodiploid clones: 44,XX,dic(3;22)(p11;q13) or der(3)t(3;22)(p11;q?) add(22)(q?),der(9;21)(q10;q10),der(13)t(1;13)(q11;p13)/45,XX,−3,der(9;21)(q10;q10),der(13)t(1;13)(q11; p13),?der(22)t(3;22)(q22;q13),+mar. The karyotypic features of this BMPA thus differ from the characteristic cytogenetic findings in pleomorphic adenomas and carcinomas ex pleomorphic adenoma.