Density distribution and antigenic characterization of cell subpopulations isolated from cystic fluids of ovarian serous neoplasms.

The immunological reactivity of serous ovarian tumor cells was evaluated, taking into account their density and morphological features. Discontinuous density gradient centrifugation was applied to fractionate cell subpopulations from cystic fluids of patients with ovarian serous carcinomas, cystadenomas and benign serous cysts. For phenotypic characterization of tumor cell subpopulations the immune sera against perchloric acid extracts of ovarian serous (anti-PCA-CaOs) and mucinous (anti-PCA-CaOm) carcinomas were used. The expression of carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) on tumor cell fractions was also checked. Some relationship between immunological reactivity, cell morphology and cell density was found; however, individual patient-to-patient variations in cellular composition and antigenic expression were also observed. The presence of ovarian serous carcinoma-associated antigen (CaOs-Ag) was related mainly to frankly malignant cells. Neither CEA nor NCA were constant and characteristic markers for serous ovarian neoplasms. These neoplasms were unreactive with anti-PCA-CaOm serum. Our results indicate the possibility of correlation between morphological features, density distribution and immunological phenotypes of ovarian tumor cell populations.