組織学的に悪性所見を呈した食道顆粒細胞腫の1例

Malignant Granular Cell Tumor of the Esophagus, Report of a Case

要旨　患者は44歳の男性．毎年胃検診を受けていたが，1989年の胃X線検査で食道に異常を指摘された．内視鏡検査では下部食道前壁にびらんを伴う隆起性病変が認められた．生検で顆粒細胞腫と診断し，内視鏡的ポリペクトミーを施行した．腫瘤は2.0×1.8×1.0cmの大きさで上皮はpseudoepitheliomatous hyperplasiaを呈し，腫瘍細胞には好酸性顆粒が存在し，散在性に異型度の強い腫瘍細胞がみられた．免疫組織化学的検討ではS-100蛋白が陽性であった．3か月後の内視鏡検査で同部位に再び腫瘍が発育し，生検で悪性所見がみられたため手術が行われた．リンパ節転移は認めなかったが，組織学的に悪性と診断された食道の顆粒細胞腫の1例を文献的考察を加え報告した．

　A 44-year-old male was admitted to our hospital because of the necessity of further examination of an esophageal polyp. He had undergone annual mass survey for stomach cancer revealing no abnormality until 1989, when a polypoid lesion was found in the lower esophagus. Esophagoscopy revealed a sweetcorn-like lesion in the lower esophagus and biopsy specimens exhibited features of granular cell tumor. Endoscopic polypectomy was performed. The surface of the resected tumor, 2.0×1.8×1.0 cm in size, was covered by pseudoepitheliomatous hyperplastic cells. There were acidophilic granules in tumor cells, some of which were atypical microscopically. Immunohistochemically, the tumor cells were positive for S-100 protein. Follow-up endoscopy perfomed 3 months later revealed a recurrent tumor in the same region. Because of the biopsy findings indicative of malignancy, esophageal resection was carried out. Review was made on 4 cases of malignant granular cell tumor of the esophagus, including the one presented here, reported to date in Japan.