Well-differentiated mucinous carcinoma of the ovary and a coexisting Brenner tumor both exhibit amplification of 12q14-21 by comparative genomic hybridization.

Although the coexistence of mucinous ovarian neoplasms and Brenner tumors is well established, the histogenesis and developmental relationship between the two remain unknown. We used comparative genomic hybridization to analyze two such tumors occurring simultaneously, one in each ovary, in a patient. Amplification of 12q14-21 sequences was found in both tumors; in addition, both tumors also had other, different changes, four identified in the Brenner tumor and six in the mucinous carcinoma. The occurrence of the same genetic alteration in both tumors in this woman suggests that the mucinous carcinoma and Brenner tumor may be clonally related, i.e., one arose from the other by means of metastatic spreading of transformed cells from one ovary to the other. An alternative explanation is that some unknown, putative tumorigenic agent induced similar and synchronous pathogenetic changes in the epithelium of both ovaries. The phenotypic differences between the tumors are presumably attributable to the other unique genetic abnormalities identified in both tumor types.