Role of ascitic and peritoneal fluid effusion cytology in predicting intraperitoneal metastasis of malignant ovarian germ cell tumors.

INTRODUCTION

Peritoneal cytology (PC) is a useful predictor of ovarian surface involvement and intraperitoneal metastasis in epithelial malignancies. Most malignancies involving serous cavity effusions are adenocarcinomas; however, nonepithelial tumors such as lymphomas and germ cell tumors (GCTs) rarely cause malignant effusion. Data on PC in malignant ovarian germ cell tumor (MOGCT) are limited to isolated case reports with lack of systematic cytohistologic correlation, hence the need for this study.

MATERIALS AND

METHODS

All PC samples of surgically resected MOGCTs were classified using The International System (TIS) for the Reporting of Serous Cytopathology. Immunohistochemistry (IHC) was performed on cell blocks of all atypical and malignant cases. Tumor markers and histopathological parameters of surgical resection specimen were correlated with cytology findings using statistical tests.

RESULTS

Nine (19%) of 48 MOGCTs showed features suspicious or definitive for metastasis on PC with three cases initially misdiagnosed as carcinomas. Spalt-like transcription factor 4 IHC resulted in upgradation of one TIS3 category case to TIS4/5. Cytological detection of metastasis correlated with intra-abdominal spread, omental involvement, and advanced pathological stage (P< 0.05).

CONCLUSIONS

Cytological detection of intraperitoneal MOGCT metastases on PC correlates with other histopathological staging parameters. Cell blocks and Spalt-like transcription factor 4 IHC aided in confirming MOGCT origin in ambiguous and misdiagnosed cases. Further validation of atypia of undetermined significance is warranted to improve diagnostic accuracy.