大網原発巨大GIST の1切除例

We report a case of giant gastrointestinal stromal tumor（GIST）primarily occurred in the greater omentum. A７８-year-old woman was referred to our hospital because of a giant abdominal tumor. Contrast-enhanced abdominal computed tomography（CT）showed a giant tumor measuring ２０×２４×１３cm in diameter in the abdominal cavity, consisting of heterogeneously enhanced solid and cystic lesions. Abdominal magnetic resonance imaging（MRI）after ３ weeks from the first medical examination showed the enlarged tumor measuring２４×２５×１７cm in diameter, the intensity of the solid lesion was low on T１weighted image, heterogeneously enhanced on T２weighted image and high on diffusion weighted image. At surgery, we confirmed the giant tumor continued to the omentum, and pressured the stomach, pancreas, and colon. The resected specimen weighed ８，３２５g containing of５，６４０ml of red-brown fluid. Histological examination showed the tumor consisted of proliferated spindle cells in a fascicular pattern and polynesic hemorrhage and necrosis. Immunohistochemically, the tumor cells were positive for c-kit and CD３４, and negative for S‐１００ protein and desmin, indicating a GIST in the greater omentum. The mitotic figures were in a４０／５０ high power field. In genetic testing, the tumor cells had exon１１mutation of c-kit gene. The woman started taking imatinib after operation and remains alive and recurrence-free.

四国医学雑誌 : http://www.tokushima-u.ac.jp/med/research/shikoku_acta_medica.html