若年性大腸癌が先行した皮膚筋炎の1例

Dermatomyositis Preceding Carcinoma of the Colon in a Young Adult, Report of a Case

要旨　患者は29歳，女性で，全身の筋肉痛・筋力低下を主訴に来院した．臨床所見，検査所見より皮膚筋炎と診断された．悪性腫瘍合併の検索のため大腸X線・内視鏡検査を施行したところ，横行結腸に2型大腸癌を認め，またUS・CTから肝左葉に孤立性の転移巣が疑われた．横行結腸癌肝転移と診断し，横行結腸切除術兼肝左葉切除術を施行した．病理組織学的には大腸原発性の高分化腺癌および肝転移と診断された．患者は術後31か月現在，外来で経過観察中であるが，皮膚筋炎の症状は消失しており癌再発も認めていない．以上，大腸癌の発生が皮膚筋炎発症の何らかの要因となったと思われる若年女性症例を若干の文献的考察を加え報告した．

　A 29-year-old woman was admitted to our hospital complaining of general myalgic pain and muscular weakness. A diagnosis of dermatomyositis was made after physical and laboratory examinations and muscle biopsy. In order to examine whether a malignant tumor was involved or not, barium enema study was carried out. It revealed "apple core" appearance in the transverse colon. Colonoscopy and endoscopic biopsy confirmed the diagnosis of carcinoma of the colon. CT scan and ultrasonography revealed a solitary mass, suggestive of metastatic tumor, in the left lobe of the liver. Under the diagnosis of carcinoma of the transverse colon with liver metastasis, transverse colectomy and left hepatic lobectomy was performed. Macroscopic findings of the resected specimen revealed colonic cancer of type 2. Histologically, well differentiated adenocarcinoma in the transverse colon with liver metastasis was found. The patient has had neither symptoms of dermatomyositis nor recurrence of cancer for the 31 months since the operation.

　In this case, colonic cancer seemed to play some part in the etiology of dermatomyositis.