Atypical papillary proliferation in gynecologic patients: a study of 32 pelvic washes

Papillary clusters in gynecologic pelvic washes frequently cause diagnostic challenges because they can be associated with borderline or malignant ovarian tumors, as well as benign pelvic diseases. The objective of our study was to review all pelvic washes with atypical papillary proliferation (APP) and investigate whether cytomorphology and/or immunohistochemistry on cell block could determine their origin. Thirty-two pelvic washes from 31 patients containing APP were reviewed and correlated with their corresponding gynecologic or pelvic disease. Previously obtained cell blocks with immunohistochemical (IHC) stains were reviewed also. Nine of 32 washes (28%) were overcalled as malignant and were from patients with 5 borderline serous ovarian tumors (BSTO), 1 ovarian follicular cyst, 1 serous cystadenofibroma, and 1 endometrial carcinoma with ovarian seromucinous cystadenoma. BSTO and endometriosis were the most common sources of APP. Cell blocks could not discriminate further the etiology of APP. Immunohistochemistry was performed rarely and not fully contributory. Caution in interpreting papillary groups and cytohistological correlation is recommended to prevent a high false positive rate.