Early cystoadenocarcinoma of vermiform appendix simulating submucosal tumor of the cecum.

Colonoscopy was performed on a 54-year-old man with occult melena in our hospital. A submucosal tumor with a maximum diameter of 5cm was detected in the cecum. The tissue of the submucosal tumor was not obtained by endoscopic biopsy, and tumor diagnosis could not be confirmed by this method. A large, hypodense, cystic structure extending below the inferior wall of the cecum was revealed by computed tomography (CT). Because the tumor was too large to be a benign tumor, we were able to conclude it was malignant. After receiving informed consent from the patient, laparoscopic right colectomy was performed for both diagnosis and treatment in June 2004. As the swollen vermiform appendix pressed the cecum extraluminally, endoscopic examination indicated the possibility of submucosal tumor. Postoperative pathological diagnosis was cystoadenocarcinoma, the tumor was extended within the mucosal layer, and no lymph node metastasis was detected. Cancer cells were not present in the viscous liquid of the vermiform appendix intracavitary, either. The patient left the hospital in 10 days postoperatively. He regularly underwent examinations including CT, and no recurrence was detected for more than 24 months following the laparoscopic operation.