Primary peritoneal serous papillary carcinoma: a clinical and pathological study.

Primary peritoneal serous papillary carcinoma (PPSPC) is a rare primary tumor of the peritoneum that found predominantly in elderly and post-menopausal women. The aim of our study is to review the clinical and pathologic information of 22 patients, and then try to summarize clinical behavior and pathological characteristics of PPSPC, in order to be better recognized of this entity in future. We retrospectively reviewed the data from 22 patients with PPSPC treated at our hospital from 1992 to 2008. All paraffin blocks were recut for periodic acid-Schiff diastase and immunohistochemical staining for CD15, cytokeratin7(CK7), cytokeratin20(CK20), S-100 protein, carcinoembryonic antigen (CEA), CA125, estrogen receptor(ER) and progesterone receptor(PR). The median age of the patients at the time of surgical staging was 56 years (range, 32-77 years). The most common presenting symptoms were abdominal distension (59.1%) and ascites (63.6%). Pretreatment CA125 levels were significant elevated in 90.5% patients. Optimal debulking was performed in 18 patients. All patients were consequently treated with platinum-based chemotherapy. Response to treatment is promising, and the median overall survival of all patients was 21.0 months (95% CI 16.9, 25.1 months). The positive rate of immunohistochemical staining was CD15 95.5%, CK7 90.9%, S-100 protein 68.2%, CA125 59.1%, CK20 31.8%, ER 31.8%, CEA 27.3% and PR 9.1%, respectively. Gynecologist should be aware of PPSPC when abdominal distension, gross ascites and a raised level of CA125 in women without ovarian enlargement. Immunohistochemical staining might be helpful as accessory criteria for the differential diagnosis among the PPSPC, peritoneal malignant mesothelioma (PMM), primary epithelial ovarian carcinoma (PEOC) and peritoneal carcinomatosis from the gastrointestinal tumors (SPCGT). Cytoreductive surgery combined with pre/postoperative platinum-based chemotherapy may be effective for PPSPC patients.