Cytogenetic analysis of a primary salivary gland myoepithelioma

Myoepithelioma, a rare benign salivary gland neoplasm, is a tumor composed entirely of myoepithelial cells. Unlike pleomorphic adenoma, these tumors l ack any ductal epithelial differentiation, and manifest a minor stromal ele ment. Previous cytogenetic and molecular genetic studies have mainly invest igated pleomorphic adenomas and reported recurring specific chromosomal alt erations at 8q12 and 12q13 similar to q15 regions. The cell origin of these alterations, however, remains speculative. We report the cytogenetic analy sis of a parotid myoepithelioma and discuss the putative origin for the cel ls with cytogenetic alterations. Our analysis shows 12q12 involved in a tra nslocation with a previously unreported partner (1q), and nonrandom del(9)( q22.1q22.3) and del(13)(q12q22). Our results indicate that the myoepithelia l cell is the source of those cells with chromosomal alterations, and that myoepithelioma shares 12q alterations reported in a subset of pleomorphic a denomas. (C) Elsevier Science Inc., 1999. All rights reserved.