Vimentin陽性胃癌の1例

Co-expression of Vimentin and Cytokeratins in Gastric Carcinoma, Report of a Case

要旨　患者は32歳，女性．胃上部大彎に，中心に深い潰瘍を有し，なだらかな立ち上がりの馬蹄型隆起を主体とする病変を見い出した．隆起の表面はイクラ状を呈していた．生検にて低分化型腺癌と診断された．胃全摘，膵・脾合併切除術を施行したが，大動脈周囲リンパ節にも転移を認めた．切除標本にて腫瘍は最大径11.8cm，肉眼分類上5型癌であり，組織学的には腺管構造を認めず，胞体成分の乏しい異型細胞が充実性に増殖し，胃壁全層に浸潤していた．免疫組織学的検索ではvimentinとcytokeratinが陽性であり，両者陽性の低分化型腺癌と判断した．術後約1か月後には多発肝転移が出現，その後も腹腔内を中心とした広範なリンパ節転移，癌性腹膜炎を来し，診断から約10か月後に死亡した．vimentin陽性胃癌は，より未成熟な細胞レベルでの癌化と推察され，生物学的悪性度が極めて高いと考えられた．

　A 32-year-old female was admitted to our hospital for further examination of epigastralgia. X-ray and endo-scopic examination showed a large fungating-type tumor in the greater curvature of the upper third of the stomach. As biopsy revealed that it was a poorly differentiated adenocarcinoma, an operation was performed under the diagnosis of advanced gastric cancer.

　Histopathological examination of the resected tumor, measuring 11.8×11.6 cm, showed that the tumor cells were polygonal in shape with scanty cytoplasm and the nuclei were pleomorphic.

　Immunohistochemically, tumor cells were diffusely positive for vimentin and cytokeratin. The lesion was finally diagnosed as poorly differentiated gastric carcinoma with co-expression of vimentin and cytokeratins. The patient developed multiple metastasis in many organs and died 10 months postoperatively.