食道・胃噴門部に発生した悪性黒色腫の1切除例

Malignant Melanoma in the Esophagus and Stomach, Report of a Case

要旨　患者は48歳の男性．上部消化管内視鏡検査で食道胃境界部直上に表面平滑な小豆大の黒色隆起と，胃噴門部に内部灰白色の潰瘍を有した粘膜下腫瘍様の隆起性病変を認めた．生検の結果，悪性黒色腫と診断され，下部食道・胃全摘，脾合併切除，2群までのリンパ節郭清を施行した．食道側の病変のH・E染色像では，腫瘍は紡錘形の異型細胞が不規則な束状配列を呈して増殖し，メラニン色素顆粒を散見した．また，腫瘍辺縁の食道粘膜ではjunctional activityを認め，一部粘膜筋板まで浸潤していた．胃側の2個の病変に連続性はなく，メラニン色素顆粒は認められなかった．食道・胃両病変はいずれもS-100蛋白強陽性を示した．

　Malignant melanoma in the esophagus in an infrequent primary neoplasm and has been reported in less than 50 cases. Also only one case of a primary gastric melanoma has been reported in the Japanese literature. Here we report a rare case of malignant melanoma, in which the primary site, either in the esophagus or sto-mach, could not be determinated.

　A 48-year-old male visited our hospital complaining of upper abdominal pain. The findings from esophagogastroscopy confirmed a dark elevated smooth-surface tumor surrounded by dark spots, just above the esophago-gastric junction. The fundic lesion was found to be a submucosal tumor with a grayish ulcer and another submucosal tumor the size of the tip of the little finger with a central depression was also found on the gastric greater curvature. The biopsy specimens from the tumors in the gastric fundus were diagnosed as being malignant melanomas. Lower esophagectomy, total gas-trectomy with splenectomy and second level lymph node dissection were carried out.

　Four courses of DVA chemotherapy were used following the surgery. However, metastasis to the liver was found to have occured a year and two months following the surgery. The patient died of liver insufficiency two years and one month after the operation.

　The lower esophagus was suspected to be the primary site of cancer because the pathological findings revealed junctional changes and esophageal melanocytosis in the resected esophagus. However the possibility of the tumor having originated in the stomach could not be eliminated. We discussed and reviewed this rare unusual case.