Takahashi Yoshihisa, Shimizu Seiichiro, Sakurai Shinji, Kumagai Arisa, Mori Shigeo, Fukusato Toshio
Department of Pathology, Teikyo University School of Medicine, Kaga, Itabashi-ku, Tokyo, Japan.
Pathol Int. 2009 Feb;59(2):98-101. doi: 10.1111/j.1440-1827.2008.02335.x.
Reported herein is a gastrointestinal stromal tumor (GIST) that exhibited a hemangiopericytoma (HPC)-like histological pattern. Such a morphological variant of GIST has not been described previously. A 57-year-old woman presented with bloody stools. On upper digestive tract endoscopy a submucosal tumor of diameter 2 cm was detected at the duodenal bulb, and enucleated. Grossly, the tumor was well-circumscribed, grayish to whitish, and solid, and its central portion was ulcerated. Histology indicated round to fusiform tumor cells that had proliferated around branching vessels that had a staghorn configuration. Immunohistochemistry showed that the tumor cells were diffusely positive for vimentin and KIT; partially positive for CD34 and muscle actin; and negative for alpha-smooth muscle actin. On mutation analysis a 42 bp deletion was found from codons 560 to 573 of exon 11 of the KIT gene, which is a mutational hot spot of GIST. In diagnosis of gastrointestinal tract tumors with an HPC-like histological pattern, pathologists should consider the possibility of GIST.
本文报道了一例表现为血管外皮细胞瘤（HPC）样组织学模式的胃肠道间质瘤（GIST）。这种GIST的形态学变异此前尚未见报道。一名57岁女性因便血就诊。上消化道内镜检查发现十二指肠球部有一个直径2 cm的黏膜下肿瘤，并将其摘除。大体上，肿瘤边界清晰，呈灰白色至白色，质地坚实，中央部分有溃疡形成。组织学显示圆形至梭形肿瘤细胞围绕呈鹿角状分支的血管增生。免疫组化显示肿瘤细胞波形蛋白和KIT弥漫性阳性；CD34和肌动蛋白部分阳性；α-平滑肌肌动蛋白阴性。突变分析发现KIT基因第11外显子第560至573密码子处有42 bp的缺失，这是GIST的一个突变热点。在诊断具有HPC样组织学模式的胃肠道肿瘤时，病理学家应考虑GIST的可能性。
