小腸多発悪性黒色腫の1例

Multiple Malignant Melanomas of the Small Intestine：a Case Report

要旨●小腸悪性黒色腫は術前診断例の報告がほとんどなく手術標本での病変評価が多いが，本症例は内視鏡的に病変を観察できた興味深い症例であるため報告する．患者は70歳代後半，男性．主訴は腹部膨満感．精査の結果，多発する小腸腫瘍とそのひとつが腸重積を起こしていた．保存的加療では軽快しないため手術となったが，その前に行った内視鏡像から悪性黒色腫を強く疑った．病理結果は粘膜下層を主座とする多発性充実性腫瘍で，褐色顆粒を有する豊富な細胞質と目立った核小体を伴う不整形の核を有しており，悪性黒色腫と診断した．本例では悪性黒色腫が組織学的に小腸原発であるとの確定診断は得られなかった．さらに全身検索を行ったが，他部位に原発巣を指摘できなかった．

　We experienced a case with multiple malignant melanomas only in the small intestine, and whether it was a primary or secondary lesion was unclear, even when the patient did not exhibit any other evident lesions.

　A man in his seventies with abdominal distension was admitted to our hospital. Computed tomography showed multiple small intestinal tumors with intussusception. We performed enteroscopy and a large, crater-like, ulcerating tumor with black and gray color was observed. We diagnosed the patient with possible malignant melanoma of the small intestine. Segmental ileal resections of the tumors were performed. Pathological examination revealed that these tumor cells had brownish granules and oval and irregular nuclei with extinct nucleoli, which suggested a final diagnosis of intestinal malignant melanoma.