Takekawa Yoshinori, Kimura Michiaki, Sakakibara Miyuki, Yoshii Riko, Yamashita Yuka
Department of Pathology, Yokosuka City Hospital, Yokosuka.
Rinsho Byori. 2007 Jun;55(6):535-9.
Gastrointestinal stromal tumor (GIST) usually occurs in the gastrointestinal tract, mainly in the stomach. Recently, GIST arising in extragastrointestinal organs was been reported. This case was a 49-year-old female who was diagnosed as having uterine leiomyoma and pelvic tumor in the rectovaginal septum. The pelvic tumor showed no connection with the uterus and rectum. Grossly, the pelvic tumor was light brown and solid. Cytologically, the tumor cells of the pelvic tumor showed vague interlacing fascicles with spindle/fibrous cytoplasm and elongated nuclei. No necrosis or mitosis was present. Histological findings of the pelvic tumor revealed an interlacing bundle fashioned with one to two mitotic figures per 50 HPE No necrosis was found in the tumor. The tumor cells were positive for CD117 (c-kit protein), CD34, and vimentin by immunohistochemistry, but negative for actin, desmin, and S-100. The tumor was diagnosed as GIST in the pelvic cavity. GIST rarely presents in extragastrointestinal regions such as this case. It is difficult to make a differential diagnosis between GIST and other mesenchymal spindle cell tumors only from a cytologic specimen. A positive reaction for CD117 is useful for the diagnosis of GIST.
胃肠道间质瘤（GIST）通常发生于胃肠道，主要在胃部。近来，有报道称GIST可发生于胃肠道外器官。该病例为一名49岁女性，被诊断患有子宫平滑肌瘤及直肠阴道隔盆腔肿瘤。盆腔肿瘤与子宫和直肠无关联。大体上，盆腔肿瘤呈浅褐色，质地坚实。细胞学检查显示，盆腔肿瘤细胞呈模糊的交织束状，胞质呈梭形/纤维状，细胞核细长。未见坏死及核分裂象。盆腔肿瘤的组织学检查发现呈交织束状，每50个高倍视野有1至2个核分裂象，肿瘤内未发现坏死。免疫组化显示肿瘤细胞CD117（c-kit蛋白）、CD34和波形蛋白呈阳性，但肌动蛋白、结蛋白和S-100呈阴性。该肿瘤被诊断为盆腔GIST。GIST很少像本病例这样出现在胃肠道外区域。仅从细胞学标本很难对GIST与其他间叶性梭形细胞肿瘤进行鉴别诊断。CD117阳性反应对GIST的诊断有帮助。
