悪性黒色腫の胃・小腸転移の1症例

A Case of Metastatic Gastrointestinal Melanoma

　胃および小腸への悪性腫瘍の転移は，しばしば報告されており，決して少ないとはいえない^1)～3)．しかし，その多くは剖検による報告で生前に臨床的に診断される例は数少ない．その中で悪性黒色腫は，これら転移性腫瘍中に占める頻度が相対的に高く，Pomerantz⁴⁾らが胃転移のレントゲン所見として紹介した“Bull's eye” signを呈した例も文献上に散見される^5)～7)．

　今回，われわれは消化管透視にて上記所見を呈し，転移性胃小腸悪性黒色腫と診断，4カ月後再検する機会を得，病理学的にも実証された1症例を経験したので報告する．

　The patient, a 32-year-old man, with malignant cutaneous melanoma had upper abdominal pain during his clinical follow-up course.

　X-ray examination of gastrointestinal tract revealed multiple metastatic lesions with so-called typical “Bull's eye” sign. Endoscopic examination of the stomach confirmed multiple submucosal tumors, measuring 12 to 20 mm in diameter, with central ulcer. From some of them, bleeding was observed. Distribution of the gastric lesions were somewhat chara-cteristic, situated mainly on the anterior wall of the fundus and body. No. tumors were found on the posterior wall or in antral region.

　On the second examination of upper gastrointestinal tract four months later, marked increase in size and number of the lesions with enlargement of the central ulcer was observed. No definite central ulcers were found in the lesions of small bowel.

　Althogh gastrointestinal involvement of malignant melanoma is not uncommon and radiological findings of “Bull's eye” sign is not pathognomonic for metastatic malignant melanoma, distribution of “Bull's eye” lesions in the stomach, and also no evidence of the central ulcer in the small intestinal lesion are of interest.