Rapid progression of submucosal invasive micropapillary carcinoma of the colon in progressive systemic sclerosis: report of a case.

A 71-year-old woman presented with hematochezia and narrowing of the stool. She suffered from progressive systemic sclerosis for 12 years and underwent home oxygen therapy due to pulmonary fibrosis and moderate pulmonary hypertension. Colonoscopy revealed a pedunculated, cauliflower-like polyp with a depressed surface in the sigmoid colon. The polyp was regarded as early colon cancer with possible submucosal invasion, and subsequent computed tomographic (CT) scans showed no evidence of lymph node involvement or distant metastases. Because of perioperative risks due to moderate pulmonary hypertension, she underwent an endoscopic resection of the early colon cancer. Pathological examination of the resected specimen of 20 mm diameter revealed the peculiar morphology of an adenocarcinoma with moderate lymphatic invasion. Immunohistochemical analysis for epithelial membrane antigen showed the specific 'inside-out growth pattern' indicative of invasive micropapillary carcinoma (IMPC). Taking the perioperative risks into consideration, she opted to undergo close follow-ups without an additional sigmoidectomy. At 6 months after the resection, the follow-up colonoscopy revealed a local recurrence of the colon cancer, and subsequent CT scans revealed multiple distant metastases including the lung, liver, lymph nodes and spleen. This is a rare case of a pure, submucosal IMPC of the colon. Furthermore, pure IMPC of the colon may represent a reliable predictor of lymphogenous and/or hematogenous metastases. Therefore, one should recommend an additional colectomy after endoscopic mucosal resection treatment when pathological findings confirmed IMPC of the colon and should continue a close follow-up for IMPC patients even when curative resections were performed at an early stage.