Rare clinical manifestations of primary peritoneal serous carcinoma presenting as colorectal cancer: A report of two cases

Objective: To report two cases of for primary peritoneal serous carcinoma (PPSC) to present with gastrointestinal manifestations that mimic colorectal cancer. Case report: There were two patients with initial presentations of fatigue with iron deficiency anemia, and tenesmus with bloody stool. Tumors of the ascending colon and rectum were detected by colonofiberoscope, and pathologic reports of tumor biopsies revealed adenocarcinoma of suspected gynecologic origin. Both patients underwent optimal debulking surgery without macroscopic residual tumor, and then received adjuvant carboplatin and paclitaxel chemotherapy with bevacizumab. Conclusions: PPSC can clinically present like primary colorectal carcinoma. The differential diagnosis requires special staining of several markers for tumor tissues.