Vij Mukul, Agrawal Vinita, Pandey Rakesh
Department of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences. Lucknow, India.
JOP. 2011 Mar 9;12(2):200-4.
Gastrointestinal stromal tumors are CD117 (C-Kit) positive mesenchymal neoplasms considered to originate from the interstitial cells of Cajal. Gastrointestinal stromal tumors have been described outside the gastrointestinal tract in sites, such as the mesentery, omentum and retroperitoneum; however, pancreatic extra-gastrointestinal stromal tumors are extremely rare and there have only been seven previous reports in the literature.
We describe a 38-year-old man with a malignant pancreatic gastrointestinal stromal tumor. The tumor was located in the head of pancreas, measured 6.5x5.0 cm and was well circumscribed. On histology, it showed a mixed spindle and epithelioid cell morphology with the presence of sheets and short intersecting fascicles of tumor cells. The mitotic count was 12-15 mitoses per 50 high-power fields. The differential diagnosis included a pancreatic smooth muscle tumor and a neuroendocrine tumor. Immunohistochemistry revealed diffuse cytoplasmic positivity for CD117 and vimentin. Tumor cells were negative for CD34, S100, desmin, smooth muscle actin (SMA), cytokeratin, neuron specific enolase, chromogranin and synaptophysin. The patient developed isolated liver metastasis two years after the resection of the primary tumor. The resected metastasis showed a similar tumor. The patient was treated with imatinib mesylate and the post-operative course two years after resection of the liver metastasis has been uneventful.
We report a rare case of pancreatic gastrointestinal stromal tumor presenting as a solid neoplasm and review the cases previously described in the literature.
胃肠道间质瘤是CD117（C-Kit）阳性的间叶性肿瘤，被认为起源于Cajal间质细胞。胃肠道间质瘤已被描述于胃肠道外的部位，如肠系膜、网膜和腹膜后；然而，胰腺外胃肠道间质瘤极为罕见，文献中此前仅有7例报道。
我们描述了一名38岁患有恶性胰腺胃肠道间质瘤的男性。肿瘤位于胰头，大小为6.5×5.0 cm，边界清晰。组织学上，其表现为梭形细胞和上皮样细胞混合形态，存在肿瘤细胞片层和短的交叉束状结构。有丝分裂计数为每50个高倍视野12 - 15个有丝分裂象。鉴别诊断包括胰腺平滑肌瘤和神经内分泌肿瘤。免疫组化显示CD117和波形蛋白弥漫性胞质阳性。肿瘤细胞CD34、S100、结蛋白、平滑肌肌动蛋白（SMA）、细胞角蛋白、神经元特异性烯醇化酶、嗜铬粒蛋白和突触素均为阴性。患者在原发肿瘤切除两年后出现孤立性肝转移。切除的转移灶显示为类似肿瘤。患者接受甲磺酸伊马替尼治疗，肝转移切除术后两年的病程平稳。
我们报告了一例罕见的表现为实性肿瘤的胰腺胃肠道间质瘤病例，并回顾了文献中先前描述的病例。
