A Case of Invasive Micropapillary Carcinoma of the Sigmoid Colon with Edema of the Lower Extremities as the Presenting Symptom

Abstract

An 86-year-old woman presented with bilateral edema of the lower extremities. Abdominal CT revealed marked swelling of the para-aortic lymph nodes and wall thickening of the sigmoid colon, however, no obstruction of the inferior vena cava was observed. Thus, the lower extremity edema was diagnosed as lymphedema. Colonoscopy revealed a type 2 tumor resembling a submucosal tumor in the sigmoid colon. Biopsy examination revealed micropapillary carcinoma, however, the microscopic appearance of the tumor was different from that of typical colorectal cancer. Accordingly, the tumor was suspected as invasive ovarian cancer or primary peritoneal cancer. Sigmoidectomy was conducted for the purpose of preventing obstruction of the colon and therapeutic diagnosis. Macroscopic examination during the operation indicated that the tumor arose from the sigmoid colon. Histopathologic examination revealed that the tumor was an invasive micropapillary carcinoma originating from the colonic mucosa. Herein, we report a case of invasive micropapillary carcinoma of the sigmoid colon that was associated with rather different clinical features and biological characteristics from those of typical colorectal cancer.