Abstract
A 40-year-old woman with a chief complaint of hematuria was evaluated in the urology department at our hospital. An intraperitoneal cystic mass was found, and she was referred to our department. Abdominal computed tomography showed a 50-mm cystic mass in the dorsal ascending colon. Surgical resection for diagnosis was planned, and ileocecal resection was performed. Histopathology revealed metastatic adenocarcinoma involving the ascending colon, but further evaluation including FDG-PET failed to identify the primary lesion.
Primary ovarian lesion was suspected, so bilateral ovariectomy was performed. However, no evidence of ovarian malignancy was identified, so unknown primary cancer was diagnosed. No postoperative chemotherapy was given, on the request of the patient, and the patient was followed-up. As of 9 months after resection of metastatic adenocarcinoma, no recurrence or primary lesion has been found, and the patient is continuing outpatient follow-up.
Lymph node metastases from cancer of unknown primary are common, but cystic metastases to the colon from unknown primary cancer have not previously been reported in Japan. We report this case of unknown primary cancer with cystic metastases to the ascending colon.
