Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
Institute of Pathology, University Hospital Cologne, Cologne, Germany.
Am J Clin Pathol. 2021 Oct 13;156(5):906-912. doi: 10.1093/ajcp/aqab045.
Hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs) were considered two distinct entities, but a common gene fusion, NAB2-STAT6, has been identified in both. Although rare, HPCs and SFTs do metastasize, some many years later after resection. Given the extended disease-free interval, it can be difficult to determine with certainty if an HPC or SFT at a new anatomic location represents a second primary or metastatic disease.
RNA was extracted from formalin-fixed, paraffin-embedded tissue of two patients with multiple SFT/HPC samples. The fusion gene was amplified by reverse transcription polymerase chain reaction (RT-PCR) and a custom-designed Archer FusionPlex panel (94 target genes) and the Illumina NextSeq 550.
We identified two patients with multiple resections for HPC/SFT during 26 years at our institution. The first patient had a history of HPC and almost 10 years later she was diagnosed with malignant SFT. The HPC and the SFT shared the same fusion breakpoint. The second patient had multiple lesions in the brain and bone/soft tissue over a 27-year span following a diagnosis of meningeal SFT. Three lesions from this patient shared the same fusion breakpoint.
Our study demonstrated the same fusion breakpoints in primary and metastatic SFTs/HPCs at different time points using both RT-PCR and the Archer fusion panel.
血管外皮细胞瘤（HPC）和孤立性纤维瘤（SFT）被认为是两种不同的实体，但两者均存在 NAB2-STAT6 基因融合。尽管罕见，但 HPC 和 SFT 确实会转移，有些在切除后多年才转移。鉴于无疾病间隔时间延长，很难确定在新解剖部位的 HPC 或 SFT 是否代表第二原发或转移性疾病。
从两名患者的福尔马林固定、石蜡包埋组织中提取 RNA。通过逆转录聚合酶链反应（RT-PCR）和定制的 Archer FusionPlex 面板（94 个靶基因）以及 Illumina NextSeq 550 扩增融合基因。
我们在本机构发现了两名 HPC/SFT 多次切除的患者，随访时间分别为 26 年和 27 年。第一例患者有 HPC 病史，近 10 年后被诊断为恶性 SFT。HPC 和 SFT 具有相同的融合断点。第二例患者在脑膜 SFT 诊断后 27 年内脑部和骨骼/软组织多处病变。该患者的三个病变具有相同的融合断点。
我们的研究使用 RT-PCR 和 Archer 融合面板在不同时间点证明了原发性和转移性 SFT/HPC 具有相同的融合断点。
