We report a case of neurofibromatosis with synchronous adenocarcinomas in the sigmoid and transverse colon. There was widespread intimal proliferation in arteries in the region of the tumors and also in the cecum. Such vascular lesions are associated with von Recklinghausen’s disease. The cecal lesion produced mural thickening visible on computed tomography. This case supports a possible genetic link between neurofibromatosis and adenocarcinoma of the colon.