Department of Pathology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
Pathol Res Pract. 2012 Aug 15;208(8):493-6. doi: 10.1016/j.prp.2012.04.008. Epub 2012 Jul 9.
Cellular solitary fibrous tumor is currently considered a synonym for hemangiopericytoma, as it became increasingly clear that the morphological and immunohistochemical features that separate these two entities have become tenuous, and evidence for a unifying concept has emerged. Furthermore, as no evidence of pericytic differentiation is given in most cases of hemangiopericytoma, this diagnostic term is waning in popularity. We present here a case of cellular solitary fibrous tumor in a 22-year-old man. Neuroimaging revealed a right cerebellopontine angle tumor. Most of the tumor was cellular although some less cellular areas were seen. Sinusoidally dilated large vessels, including staghorn type, were seen. Nuclear pleomorphism and increased mitotic activity (5 mitosis/10 high power field) were regarded as evidence of anaplasia. Diffuse CD34 immunoreactivity and focal positivity for Factor XIIIa were seen in the tumor, which was negative for EMA and S100. The tumor also displayed rich reticulin network. Solitary fibrous tumor at cerebellopontine angle is rare, and 20 such cases (five reported as hemangiopericytoma) have been reported in the English literature.
细胞性孤立性纤维性肿瘤目前被认为是血管外皮细胞瘤的同义词，因为越来越明显的是，将这两种肿瘤分开的形态学和免疫组织化学特征变得不那么明确，并且出现了一个统一概念的证据。此外，由于大多数血管外皮细胞瘤中没有给出周细胞分化的证据，因此这个诊断术语的使用正在减少。我们在此介绍一例 22 岁男性的细胞性孤立性纤维性肿瘤。神经影像学显示右侧桥小脑角肿瘤。虽然可以看到一些细胞较少的区域，但大多数肿瘤是细胞性的。可见窦状扩张的大血管，包括鹿角状类型。核异型性和有丝分裂活性增加（每 10 个高倍视野有 5 个有丝分裂）被认为是间变的证据。肿瘤弥漫性表达 CD34，部分区域表达因子 XIIIa，EMA 和 S100 均为阴性。肿瘤还显示丰富的网状纤维。桥小脑角的孤立性纤维性肿瘤很少见，在英语文献中已经报道了 20 例（5 例报告为血管外皮细胞瘤）。
