リンパ節転移を伴う微小直腸カルチノイド腫瘍に対して腹腔鏡補助下低位前方切除術を行った1例

A case of laparoscopically assisted low anterior resection for small rectal carcinoid tumor with lymph node metastasis

症例は35歳，女性．下血を主訴に受診した近医で直腸腫瘍を指摘され，紹介された．注腸造影，大腸内視鏡の所見から直腸カルチノイドと考えられた．腫瘍径は小さかったが，隆起頂部に中心陥凹を認めたためリンパ節転移のハイリスク症例と判断し，リンパ節郭清を伴う腹腔鏡補助下低位前方切除術を施行した．腫瘍は直径6mmの直腸カルチノイドであり，リンパ節転移を伴っていた．微小なカルチノイドであっても，中心陥凹を伴う場合はリンパ節転移のリスクがあると考えられ，このような症例には低侵襲かつ根治性の期待できる腹腔鏡補助下手術はよい適応であると考えられた．

　We report a case of laparoscopically assisted low anterior resection for a small rectal carcinoid tumor with lymph node metastasis. A 35-year-old female patient consulted a medical doctor with melena. Examination suggested a rectal tumor and she was introduced to Kakogawa municipal hospital. Barium enema and colonoscopy revealed a submucosal tumor with suspicion of a carcinoid tumor. Although the size of the tumor was small, central depression of the tumor surface was considered to suggest a high risk of lymph node metastasis and laparoscopically assisted low anterior resection with lymph node dissection was carried out. Histological investigation revealed a carcinoid tumor 6 mm in diameter of the rectum and metastasis to the proximal lymph node. When a carcinoid tumor of the colon and rectum has a central depression on the tumor surface, it is considered that colectomy with lymph node dissection is indicated in spite of the size of the tumor. Laparoscopic surgery is thought to be one of the good operative methods for such a case with the risk of lymph node metastasis.