Composite mucinous ovarian neoplasms associated with Sertoli-Leydig and carcinoid tumors.

The authors describe two mucinous ovarian tumors that were hormonally active due to Sertoli-Leydig elements within the septal stroma. Carcinoid was also present in each case. The mesenchymal stromal cells within the septa of the mucinous tumors have undergone neoplastic proliferation with the Sertoli and Leydig differentiations, leading to the formation of arrhenoblastoma. The carcinoid component of these tumors is thought to have originated from argentaffin cells of the "intestinal" mucinous epithelium.