Peritoneal cytology of uncommon ovarian tumors

Peritoneal cytology has been well established as a diagnostic and staging tool in the management of the common epithelial tumors of ovary. Germ cell, mesenchymal, and sex‐cord stromal tumors are much less frequently encountered in peritoneal specimens, often with cytologic features that may pose problems in differential diagnosis. This report presents the cytomorphology of the ascitic fluid in cases of endodermal sinus tumor, dysgerminoma, and Sertoli‐Leydig‐cell tumor, and peritoneal washings in a case of ovarian malignant mixed mullerian tumor. The cytologic features of Sertoli‐Leydig‐cell tumors have not been well described. Careful correlation of peritoneal cytologic findings, cell‐block preparations, and immunocytochemistry with the cytohistologic features of these tumors is crucial for correct tumor classification.