1) Wante AL, Trevino E: Diagnostic features of mucocele of the appendix. Arch Surg 84: 516-524, 1962 2) Aho Aj, Heinonen R, Lauren P: Benign and malignant mucocele of the appendix: His tological types and prognosis. Acta Chir Scand 139: 392-400, 1973 3) Collins DC: 71,000 Human appendix speci mens: a final report summarizing study. Am J Proctol 14: 265-281, 1963 forty years' 4) Higa E, Rosai J, Pizzimbono CA, et al: Mucosal hyperplasia, mucinous cystadenoma, and mucinous cystadenocarcinoma of the appendix. A re-evaluation of a appendiceal "mucocele". Cancer 32: 1525-1541, 1973 5) Appleman HD: Epithelial neoplasia of the appendix. Ed. by Norris HT. Pathology of the colon, small intestine, and anus. Chrchill Livingstone, New York, 1991, p263-303 6) Tang C: Disorders of the vermiform appendix. Ed. by Ming S, Goldman H. Pathology of the gastrointestinal tract. WB Saunders Co., Philadelphia, 1992, p861-881 7) Qizilbash All: Mucoceles of the appendix: Their relationship to hyperplastic polyps, mucinous cystadenomas, and cystadenocar cinomas. Arch Pathol 99: 548-555, 1975 8) Wolff M, Ahmed N: Epithelial neoplasms of the vermiform appendix (exclusive of car cinoid): cystadenomas, papillary adenomas, and adenomatous polyps of the appendix. Cancer 37: 2511-2522, 1976 10) Soweid AM, Clarkston WK, Andrus CH, et al: Diagnosis and management of appendiceal mucoceles. Dig Dis 16: 183-186, 1998 11) Gibbs NM: Mucinous cystandenoma and cystadenocarcinoma of the vermiform appen dix with particular reference to mucocele and pseudomyxoma peritonei. J Clin Pathol 26: 413-421, 1973 12) Sato T, Ueda T, Kon H, et al: Mucinous cystadenoma of appendix concomitant with perityphlic granuloma. J Gastroenterol 39: 779-782, 1995 13) Dachman AH, Lichtenstein JE, Friedman AC: Mucocele of the appendix and pseudomyxoma peritonei. AJR 144: 923-929, 1985 14) Isaacs KL, Warshauer DM: Mucocele of the appendix: Computed tomographic, and pathologic correction. 87: 787-789, 1992 endoscopic, Am J Gastroenterol 15) Horgan J, Chow P, Richter J, et al: CT and

19) Aranha GV, Reyes CV: Primary epithelial tumors of the appendix and a reappraisal of the appendiceal "Mucocele". Dis Col & Rect 22: 472-476, 1979 20) Lys AP: Appendiceal malignancies. Semin Oncol 15: 129-137, 1988 TWO CASES OF RUPTURED AND NON-RUPTURED MUCINOUS CYST ADENOMA OF THE APPENDIX VERMIFORMIS Hidetaka YAMANAKA, Tomonori SUGIURA, Satoru KAWAI, Yoshimi KITAGAWA, Hiroshi KONO and Yutaka MATSUURA Department of Surgery, Nagoya Ekisaikai Hospital Mucinous cyst adenoma of the appendix vermiformis presents difficulty in diagnosis preoperatively and results in pseudomyxoma peritonei on ruptured case. We report two cases of the disease including a ruptured case. Patient 1, a 50-year-old woman, was admitted to the hospital because of right lower abdominal pain and fever up. Laboratory data showed increses in white blood cell count and CRP. She was performed an appendectomy with a partial cecectomy due to inflammatory adhesion of the appendix vermiformis to cecum, because mucocele of the appendix vermiformis with appendicitis was diagnosed on an abdominal CT scan. The definite diagnosis of mucinous cyst adenoma of the appendix vermiformis with chronic inflammation was made on the resected specimen. Patient 2, a 73-year-old woman, was admitted to the hospital because of a right lower abdominal painful mass. Colonography showed extramural compression of the cecum. On the 12th hospital day, she complained of increasing abdominal pain but it was relieved by conservative therapy. On the 16th hospital day, an abdominal CT scan showed contraction of the mesenterium at the right lower abdomen and intraabdminal pooling of mucin. The patient was diagnosed as having pseudomyxoma peritonei caused by ruptured mucocele of the appendix vermiformis, and underwent an appendectomy, removal of intraabdominally pooling mucin and irriga tion. Resected specimen revealed mucinous cyst adenoma of the appendix vermiformis and the existence of tumor cells in the removed mucin. We think to perform surgery as fast as possible after making diagnosis of the disease, because the duration from starting of inflammation to perforation appears to be relatively short.