Department of Orthopedic Oncology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
Department of Medical Genetics and Rare Orthopedic Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
Virchows Arch. 2020 Mar;476(3):445-454. doi: 10.1007/s00428-019-02650-5. Epub 2019 Aug 28.
Solitary fibrous tumor is a rare mesenchymal neoplasm that exhibits a broad spectrum of biological behaviors. Few studies relative to clinical-pathologic features and predictive factors have been reported, all involving a mixed population of tumors occurring at different anatomic sites. In this study, we described a cohort of 41 patients with solitary fibrous tumor of the extremities and evaluated the prognostic role of clinical and histological features, presence of C228T and C250T mutations at the TERT promoter region, and NAB2-STAT6 fusion variants. Patients were stratified according to the latest risk stratification model proposed by Demicco. The two patients with metastasis at presentation were in the high-risk group; the one with metastasis after surgery was classified in the intermediate-risk group. TERT promoter mutations were detected in 9 out of 38 DNA available. All patients with metastasis were characterized by a TERT promoter mutation. TERT promoter mutation was associated with mitoses > 4 per high-power field (p = 0.001), necrosis (p = 0.049), and size > 10 cm (p = 0.031). NAB2-STAT6 fusion variants were detected in 27 out of 41 cases without any prognostic value. In conclusion, we confirmed that the patients with solitary fibrous tumor of the limbs have a better prognosis than other solitary fibrous tumors, with a very low percentage of metastatic events. Besides, our data support an association between TERT promoter mutations and histologically malignant features, suggesting a possible molecular role in stratifying patients into intermediate- to high-risk tumor.
孤立性纤维瘤是一种罕见的间叶性肿瘤，具有广泛的生物学行为。很少有研究涉及到临床病理特征和预测因素，所有这些研究都涉及到发生在不同解剖部位的混合肿瘤群体。在这项研究中，我们描述了一组 41 例肢体孤立性纤维瘤患者，并评估了临床和组织学特征、TERT 启动子区域 C228T 和 C250T 突变、NAB2-STAT6 融合变体的预后作用。根据 Demicco 提出的最新风险分层模型，对患者进行分层。两名就诊时发生转移的患者属于高危组；一名术后发生转移的患者被归类为中危组。在可用的 38 份 DNA 中有 9 份检测到 TERT 启动子突变。所有发生转移的患者均表现出 TERT 启动子突变。TERT 启动子突变与有丝分裂>4/高倍视野（p=0.001）、坏死（p=0.049）和>10cm 大小（p=0.031）有关。在 41 例病例中，有 27 例检测到 NAB2-STAT6 融合变体，但无任何预后价值。总之，我们证实肢体孤立性纤维瘤患者的预后优于其他孤立性纤维瘤，转移事件的比例非常低。此外，我们的数据支持 TERT 启动子突变与组织学恶性特征之间的关联，提示 TERT 启动子突变可能在将患者分层为中高危肿瘤方面具有潜在的分子作用。
