短期間で縮小を認めた低異型度虫垂粘液性腫瘍に対して腹腔鏡下盲腸部分切除術を施行した1例

A case of laparoscopic partial cecal resection of a low-grade appendiceal mucinous neoplasm with rapid size changes

◆要旨：症例は80歳台，女性．数年前より年に1回腹痛を自覚し，そのたびに前医で抗菌薬により改善を認めていた．今回も同症状で前医を受診し，血液生化学的検査で炎症反応の上昇を認め，抗菌薬を内服したが改善しなかった．単純CTで右骨盤底に70×40mm大の囊胞性病変を認め，右卵巣腫瘍疑いで当院産婦人科に紹介された．2週間後の造影CTで28×14mm大と著明な縮小傾向を認め，腸管内に内容物がドレナージされた虫垂粘液性腫瘍を疑い，腹腔鏡下盲腸部分切除術を施行した．病理検査では低異型度虫垂粘液性腫瘍（low-grade appendiceal mucinous neoplasm : LAMN）の診断であった．術後2年半の現在も無再発生存中である．短期間に著明なサイズ変化を伴う右骨盤内腫瘍は，LAMNを考慮する必要がある．

　The patient was a female in her 80s, who had experienced abdominal pain once a year for several years. Each time, her primary care doctor treated her with antimicrobial agents. She recently complained of the same symptoms and visited the same doctor. Blood biochemical tests revealed an elevated inflammatory response that did not improve despite antimicrobial therapy. Computed tomography（CT）revealed a cystic lesion measuring 70×40mm in the right pelvis, and the patient was referred to our obstetrics and gynecology department with suspicion of a right ovarian tumor. Two weeks later, a contrast-enhanced CT scan revealed a marked decrease in size to 28×14 mm, which ruled out an ovarian tumor. The patient was subsequently suspected of having an appendiceal mucous tumor whose content has drained into the intestinal tract. Laparoscopic partial cecal resection was performed. The intraoperative findings revealed severe appendicitis and adhesion to the right fallopian tube, which were resected simultaneously. The pathological diagnosis was a low-grade appendiceal mucinous neoplasm（LAMN）. The patient has since remained under observation without recurrence. LAMN should be considered as a diagnosis for right pelvic tumors with significant size changes in a short period.