Primary peritoneal serous carcinoma: a clinicopathological and immunohistochemical study of six cases.

AIMS Primary peritoneal serous carcinoma (PPSC) is an unusual neoplasm that has not been properly characterized. To better define the clinicopathological and immunohistochemical features of PPSC, we present 6 such cases. METHODS The 6 patients consisted of one man and 5 women, ranging in age from 45 and 75 years. None of the patients had any history or clinical evidence of tumor elsewhere. The immunohistochemical profile was examined using antibodies against β-catenin, E-cadherin, wnt5a, EGFR, VEGF, vimentin, Ki67, and P53. RESULTS Of all the 6 PPSC cases, 5 cases presented stage IIIC and 1 case presented stage IV. Microscopically, 5 cases were poorly differentiated and 1 was moderately differentiated. All cases showed positive staining for β-catenin, E-cadherin, vimentin, VEGF, P53, and Ki67, 4 cases expressed EGFR, and all cases were consistently negative for wnt5a. CONCLUSIONS We described 6 cases of PPSC with clinicopathological and immunohistochemical features. The findings provide basic knowledge of PPSC.