Primary peritoneal serous papillary carcinoma presenting as a single colonic mass without peritoneal dissemination.

Peritoneal serous papillary carcinoma (PSPC), a rare primary malignancy arising from the abdominal and pelvic peritoneum, is characterized by peritoneal carcinomatosis with ascites and a histological pattern similar to that of papillary serous ovarian carcinoma. We herein describe a rare case of PSPC with unusual clinical presentations involving a single primary tumor originating from the peritoneal lining of the sigmoid colon with no evidence of intraperitoneal spread, pelvic lymph node involvement or distant metastasis. Awareness of such unusual presentations of PSPC should assist in the diagnosis of this disease, thereby improving the management of patients with this condition.