Abstract
A 75-year-old male tested positive for fecal occult blood. Colonoscopy revealed an Ip-type irregular surfaced protruding lesion, measuring 9mm in the rectosigmoid colon. We performed endoscopic mucosal resection (EMR) for this lesion. Histologically, the lesion showed well differentiated adenocarcinoma, invading deeply into submucosal layer without lympatic or venous permeation. The tumor was completely removed and CT showed no signs of metastasis. But We considered the risk of lymph node metastasis and the additional surgery was recommended with lymph node dissection and low anterior resection (D2) was performed. On histopathological examination of the resected specimen, both residual cancer and lymph node metastasis were not recognized. After surgery, CT showed the solid nodule of 5mm in diameter in the apex of the right lung after 1year 10 months. After that, the tumor was enlarged from 5mm to 7mm during 9months and partial resection was performed. Histological findings of resected lung tumor showed the well differentiated adenocarcinoma same as the primary rectal lesion and was diagnosed as lung metastasis. As of 2 years 6 months after partial resection, new metastasis has not occurred. Submucosal colon cancer with metachronous pulmonary metastasis is rare. The resection of lung metastasis is expected good prognosis, therefor it is necessary to accumulate more cases and establish an appropriate surveillance.
