SEROUS SURFACE CARCINOMA OF THE PERITONEUM - USEFUL ROLE OF CYTOLOGY IN DIFFERENTIAL-DIAGNOSIS AND FOLLOW-UP

OBJECTIVE: To determine the role of cytology in differentiating serous surface carcinoma of the peritoneum (SSCP) from other morphologically similar tumors, including ovarian carcinoma and other peritoneal lesi ons, and to define the value of cytology in the follow-up of patients with SSCP. STUDY DESIGN: Twenty-one ascitic fluids and seven peritonea l washings obtained from 19 patients with histologically confirmed SSC P were reviewed and their cytologic features tabulated and analyzed. R ESULTS: Eighteen of the specimens were from initial diagnostic paracen teses or exploratory laparotomies. These showed mostly three-dimension al tumor cell clusters, as well as single malignant cells, with occasi onal papillae. The cytoplasm was abundant and often vacuolated. The cy tomorphologic features of SSCP enabled differentiation from other cond itions involving the peritoneal surface, including mesothelial hyperpl asia, malignant mesothelioma, endometriosis and endosalpingiosis. Howe ver, there were no characteristic features that differentiated SSCP fr om metastatic serous carcinoma of the ovary. Four of the peritoneal wa shings were from second-leak operations; in each of these cases the pr esence of tumor cells in the cytologic preparations correlated with po sitive biopsy results. Furthermore, six of the paracenteses were perfo rmed for recurrent ascites and enabled detection of recurrent disease, obviating the need for invasive procedures. CONCLUSION: Cytomorpholog ic examination of ascitic fluids and peritoneal washings serves a valu able role in the initial diagnosis of SSCP, in the detection of recurr ent disease and as a useful adjunct to multiple biopsies in the second -look operation. It can differentiate SSCP from several other lesions but not from serous carcinoma of the ovary.