A CASE OF MUCINOUS CYSTADENOMA OF THE APPENDIX WITH REVIEW OF THE JAPANESE LITERATURE

A 77-year-old woman was admitted to the hospital because of a right lower abdominal mass and right lower abdominal pain which had been felt for about one month but gradually aggravated. No epigastric pain, nausea, and diarrhea were noted. On admission, physical examination revealed a palpable mass 3cm in diameter in the right lower abdomen with rebound tenderness. Abdominal ultrasonography demonstrated a 20×17mm low echoic lesion and CT revealed a low density abdominal mass 2cm in diameter. Colonoscopic examination revealed obstruction of appendiceal orifice with swelling and redness of surrounding cecal mucosa. Appendectomy was performed and the diagnosis of mucinous cystadenoma was made by intraoperative frozen section. The surgical margin was positive so on ileoceal resection was performed. Histopathological study revealed a production of large quantity of mucin to form a 7×12mm cyst which was seemingly surrounded by columnar epithelial cells in monolayer; the NC ratio was small; and morphologies and sizes of nuclei were relatively homogenous with less dysplasia. The difinite diagnosis of mucinous cystadenoma of the appendix of low grade malignancy was made. The patient was discharged from the hospital on the 14th postoperative day in good condition. The patient has been well as of 3 years after the operation. Mucinous cystadenoma of the appendix is a rare disease and presents difficulty in diagnosis preoperatively. Reported cases in the Japanese literature are reviewed in terms of diagnosis and surgical procedures.