Positive peritoneal fluid cytology in ovarian malignancies with metastasis:a descriptive study

Abstract

Detection of malignant cells in peritoneal fluid and peritoneal washings obtained at laparotomy is useful in predicting the presence of peritoneal metastasis in ovarian cancer. It will help in tumour staging, planning of further management as well as predicting the prognosis. The accuracy of such predictions will depend on the diagnostic accuracy of cytology in detecting metastasis, which is expressed by sensitivity, specificity and positive and negative predictive values. We tried to determine the said parameters in a series of patients with ovarian cancer who underwent laparotomy at a tertiary care teaching hospital. Forty two consecutive patients with malignant ovarian tumours were studied with respect to differentiation, grade and size of tumour. The peritoneal fluid obtained was assessed for the presence of malignant cells and the nature (serous or blood stained) of the fluid. The accompanying omentectomy specimens were examined for histological evidence of metastasis. Nineteen out of 42 patients had histologically proven omental tumour deposits. Of these only 11 yielded positive cytology. One specimen was cytology positive in the absence of histological evidence of peritoneal deposits. The sensitivity of peritoneal fluid cytology was 57.9%, specificity was 95.7%, positive predictive value was 91.7% and negative predictive value was 76.7% in our series. Any of the characteristics in the tumour or the peritoneal fluid failed to demonstrate a significant association with positive cytology. The sensitivity of peritoneal fluid cytology in detection of peritoneal spread was low (measured against histologically proven omental deposits), which highlights the need of other adjunct methods such as biochemical markers and fluorescence in situ hybridisation to improve the diagnostic accuracy.