Dipartimento G.F. Ingrassia, Anatomia Patologica, Policlinico Universitario G. Rodolico, Università di Catania, Via S. Sofia 87, Catania 95123, Italy.
Pathol Res Pract. 2010 Jul 15;206(7):499-503. doi: 10.1016/j.prp.2010.01.002. Epub 2010 Feb 25.
The diagnosis of solitary fibrous tumor (SFT) is usually straightforward if the typical morphologic features, including a wide variety of growth patterns, are identified. We report the clinical, radiologic, and pathologic findings of a rare case of intraoral SFT which exhibited a predominant leiomyomatous-like appearance, closely reminiscent of a leiomyoma, at both incisional and excisional biopsy. Histologically, the tumor was composed predominantly of intersecting fascicles of eosinophilic spindle-shaped cells, variably set in a fibrous stroma. A focal hemangiopericytoma-like growth pattern with alternating hypercellular and hypocellular areas, as well as the deposition of dense keloid-type collagen, raising the suspicion of SFT, could be identified only after a careful examination of the whole tumor. Immunohistochemistry was helpful in confirming the diagnosis of SFT, revealing a diffuse staining of neoplastic cells for vimentin, CD34, bcl-2 protein, and, focally, CD99. Myogenic markers (alpha-smooth muscle actin, desmin, h-caldesmon) were not expressed. The pathologist should be aware of this variant of intraoral leiomyomatous-like SFT to avoid a misdiagnosis of leiomyoma. The distinction of SFT from leiomyoma in the oral cavity is important to assure both correct treatment and prognostic information.
孤立性纤维瘤（SFT）的诊断通常很简单，如果识别出典型的形态特征，包括广泛的生长模式。我们报告了一例罕见的口腔内 SFT 的临床、放射学和病理学发现，该肿瘤在切取和切除活检中均表现出主要类似于平滑肌瘤的平滑肌样外观，与平滑肌瘤非常相似。组织学上，肿瘤主要由交错的嗜酸性梭形细胞束组成，在纤维基质中呈不同程度排列。仅在仔细检查整个肿瘤后，才能识别出具有交替的细胞丰富区和细胞稀少区的局灶性血管外皮细胞瘤样生长模式，以及致密的瘢痕疙瘩样胶原沉积，这提示可能为 SFT。免疫组织化学有助于确认 SFT 的诊断，显示肿瘤细胞弥漫性表达波形蛋白、CD34、bcl-2 蛋白，偶尔表达 CD99。肌源性标志物（α-平滑肌肌动蛋白、结蛋白、h-钙调蛋白）不表达。病理学家应该意识到这种口腔内平滑肌样 SFT 变体，以避免误诊为平滑肌瘤。口腔内 SFT 与平滑肌瘤的鉴别对于确保正确的治疗和预后信息非常重要。
