直腸に2病巣を認めた直腸カルチノイドの1例

A Case Report of Rectal Carcinoid with Two Primary Lesions

　直腸に径2.0×2.0cmと径0.3×0.2cmの2病巣が併存し，腹会陰合併直腸切断術を行ない，傍直腸および上直腸動脈周囲のリンパ節転移を認めた直腸カルチノイドの1例を経験したので報告するとともに，本症の治療上の問題点についての文献的な考察を加えてみたい．

症例

　患　者：59歳　男性　農業

　主　訴：肛門不快感

　家族歴：特記すべきことなし

　現病歴：肛門不快感があり，1976年1月，痔核手術をうけたが，肛門不快感が持続するので来院，肛門指診で肛門輪より5cm口側6時の部位を中心に可動性のない腫瘤を触知した．

　The patient, a 59-year-old male, had complained of unpleasant feeling in his anal region.

　Digital examination of the rectum revealed a small hard nodule. Roentgenographically, a submucosal tumorous shadow was demonstrated on the posterior wall of the ampullar region of the rectum. Endoscopically, a Ⅱa＋Ⅱc-like lesion measuring 2.0×2.0 cm was found, located about 5 cm from the anus. A biopsy specimen was diagnosed as carcinoid histologically. The excretion of 5-HIAA into the urine was within normal limits.

　Radical operation (abdomino-perineal resection) was carried out because of the lack of mobility of the tumor mass. At the time of surgery, a tumor measuring 2.0 cm in width with superficial ulceration on its tip was excised (A). Moreover, another small tumor measuring 0.3×0.2 cm was recognized in the same surgical specimen 2 cm proximal to the anal ring (B).

　Histologically, the tumor A extended through the muscularis propria and the tumor B infiltrated the submucosal layer. Metastases to the regional lymph nodes were demonstrated histologically, but not to the liver. Electronmicroscopic examination of the tumor A showed numerous neurosecretory granules within the cytoplasma of the tumor cells, characteristic for carcinoid tumors.

　Rectal carcinoid is a rare disease and 28 cases excluding our case have been reported in Japan up to the present. Each of these cases had a solitary lesion of the rectum except for our case.