A case of mucocele of the appendix associated with an increase in serum CEA level is presented. A 71-year-old man was seen at the hospital because of cough. Chest X-ray film showed no abnormal findings. However, serum CEA level was high, 14.0ng/ml. Physical examination revealed a well movable mass with smooth surface, measuring 8×4cm, in the right lower quadrant of the abdomen. Barium enema demonstrated a filling defect with smooth contour, 6×4.5cm in size, in the cecum. Colonofiberscopy showed a round submucosal tumor-like lesion. With a preoperative diagnosis of appendiceal mucocele, ileocecal resection was performed. The resected specimen showed a markedly swollen appendix, 5cm in diameter and 15cm in length. The root of the appendix was invaginated into the cecum. The appendix was histologically diagnosed as mucinous cystadenoma without any malignant changes. Immunohistochemically, the tumor cells showed a positive stain for anti-CEA antibody. The postoperative course was uneventful and the serum CEA level returned normal, 2.5ng/ml, three months after the surgery.
To the best of our knowledge, a total of 40 cases of mucocele of the appendix have been reported in Japan from 1986 through 1993. Of these cases, serum CEA level was described in 19 cases. Six (31.6%) out of 19 cases showed an increase in serum CEA level.