Pelvic washing cytology in serous borderline tumors of the ovary using ThinPrep: are there cytologic clues to detecting tumor cells?

The detection of tumor cells in pelvic washings of patients with serous borderline tumors of the ovary (SBT) remains a diagnostic challenge. Accurate diagnosis of pelvic washings is important in determining therapeutic regimens and assessing patient prognosis. No study has exclusively examined pelvic washing cytology of patients with SBT using only ThinPrep methodology. The purpose of this study is to examine whether cytologic clues exist in detecting tumor cells of SBT in pelvic washings processed with ThinPrep. Using previously established criteria, we reviewed the pelvic washes of 37 patients with SBT and correlated them with the histologic findings in the omentum. We also compared their cytoarchitectural features with pelvic washes in patients with benign ovarian disease and serous carcinoma. Cytoarchitectural features that achieved statistical significance in distinguishing cells of a SBT from reactive mesothelial cells include the following findings: presence of a two-cell population (P = 0.001), psammoma bodies (P = 0.001), cytoplasmic vacuolization (P = 0.001), smooth group contours (P = 0.004), nuclear size >2x neutrophils (P = 0.004), high nuclear-to-cytoplasmic (N/C) ratio (P = 0.004), absent intercellular windows (P = 0.007), and course nuclear chromatin (P = 0.032). Psammoma bodies were the only statistically significant feature distinguishing SBT from serous carcinoma, being more common in SBT than serous carcinoma (P = 0.035). The prominent number of associated psammoma bodies seen in the SBT group was a notable finding that may aid as a valuable cytologic clue in detecting tumor cells. Overall cellularity remains a source of false-negative diagnosis. Correlation with histologic findings remains crucial given our inability to reliably distinguish tumor cells of SBT from endosalpingiosis or serous adenocarcinoma. Copyright 2004 Wiley-Liss, Inc.