Mucinous cystadenocarcinoma in the appendix in a patient with nonrotation: report of a case.

Mucinous cystadenocarcinoma in the appendix is uncommon. An anomaly in the rotation of the intestine is also uncommon in adults. We herein report a case of mucinous cystadenocarcinoma in the appendix in a patient with nonrotation. To the best of our knowledge, this is the first report of appendiceal carcinoma in a patient with an anomaly of intestinal rotation. A 76-year-old woman was admitted to our hospital with left low abdominal pain. Physical examination revealed tenderness with muscle rigidity in the left lower quadrant. The patient was diagnosed to have intussusception by computed tomography and ultrasonography. An emergency operation showed nonrotation and the top of the appendix situated in the left iliac fossa. An appendectomy was performed because of gangrenous acute appendicitis. However, the cut surface of the appendix showed a mucocele measuring 4 x 4 cm in size. It was diagnosed to be mucinous cystadenocarcinoma histopathologically. A right hemicolectomy with lymph node dissection was performed, and no remaining cancer cells or lymph node metastases were found in the resected specimen pathologically. The patient had an uneventful postoperative course. No signs of recurrence have been observed for 23 months since her last operation.