Peritoneal serous papillary carcinoma : radiological appearance

Background: The radiological appearance of peritoneal serous papillary carcinoma (PSPC) is described. Methods: Three cases of PSPC were analyzed retrospectively with regard to the radiological appearance and histopathological features. Results: All three patients were women, aged 44-71 years. Massive ascites and a greater omentum tumor were observed on computed tomography in all patients. Double-contrast enema performed in one patient showed irregularity on the upper aspect of the transverse colon. Radiological examinations excluded primary tumors in both gastrointestinal and genital organs in all patients. Histological diagnosis was made from the surgical specimen in two patients and from an autopsy specimen in one patient. All patients had a large omental tumor involving the transverse colon, but the ovaries were not involved or only minimally involved on the surface. Serum CA125 was markedly elevated, and immunohistochemical staining for CA125 was positive within the tumor cell cytoplasm in all three patients. Conclusion: PSPC cannot be diagnosed from radiological findings alone because of its similarity to metastatic peritoneal carcinomatosis and peritoneal mesothelioma. Marked elevation of serum CA125 may help with PSPC diagnosis. Response to treatment is promising, and exploratory laparotomy is thus justified when a patient shows characteristic radiological findings and high CA125 level.