Departments of Pathology, Daehang Hospital, Seoul, Korea.
Diagn Pathol. 2013 Jun 6;8:90. doi: 10.1186/1746-1596-8-90.
A 58-year-old woman presented with a solitary myofibroma that arose in the sigmoid colon. Computed tomography revealed a highly enhanced intramural mass (1.3-cm maximum diameter) in the proximal sigmoid colon. Histologically, the tumor exhibited a biphasic growth pattern, which comprised haphazardly arranged, interwoven fascicles of plump, myoid-appearing spindle cells with elongated nuclei and abundant eosinophilic cytoplasm, and more cellular areas of primitive-appearing polygonal cells that were arranged in a hemangiopericytomatous pattern. The tumor cells were positive for smooth muscle actin (SMA), and negative for desmin, h-caldesmon, CD34, cytokeratin, S100 protein, and CD117. The Ki-67 labeling index was not high (up to 7%). Based on these histologic and immunohistochemical features, our patient was diagnosed with a myofibroma of the sigmoid colon. The presence of solitary myofibroma in the intestine of an adult requires attention to avoid misdiagnosis as a more aggressive mesenchymal tumor.
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一位 58 岁女性因单发肌纤维瘤出现在乙状结肠而就诊。计算机断层扫描显示乙状结肠近端有一个高度强化的壁内肿块（最大直径 1.3 厘米）。组织学上，肿瘤表现出双相生长模式，由排列杂乱、交织的、丰满的、肌样梭形细胞束组成，细胞核细长，胞浆丰富嗜酸性，还有更具原始多边形细胞的细胞区，呈血管外皮细胞瘤样排列。肿瘤细胞 SMA 阳性，结蛋白、h-caldesmon、CD34、细胞角蛋白、S100 蛋白和 CD117 阴性。Ki-67 标记指数不高（高达 7%）。根据这些组织学和免疫组织化学特征，我们的患者被诊断为乙状结肠肌纤维瘤。成人肠道中孤立性肌纤维瘤的存在需要注意，以避免误诊为更具侵袭性的间质肿瘤。
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