[A Case of Pulmonary Metastases of Colon Cancer with Submucosal Invasion].

In general, distant metastasis is uncommon in colorectal submucosal(SM)invasion without lymph node metastasis. We experienced an extremely rare case of synchronous pulmonary metastases for colon cancer in SM invasion. A man in his 70s was seen at the hospital for a positive fecal occult blood test. Colonoscopy revealed 3 lesions in the sigmoid colon and endoscopic mucosalresection revealed 2,000 mm SM invasion in all 3 lesions. Computed tomography showed no signs of distant lymph node or liver metastasis but showed small nodules in both lungs. Radical treatment included laparoscopic anterior resection with lymph node dissection. Histological examination showed no residual tumor in the colon and no lymph node metastasis. Two years after surgery, the number of lung nodules gradually increased and we performed partial resection of the left lung, which was diagnosed as pulmonary metastasis from colon cancer by histological examination. Therefore, we resected the opposite-side pulmonary metastases. The patient has exhibited no other signs of recurrence in the 2 years since the last operation.