Oike Naoki, Kawashima Hiroyuki, Ogose Akira, Hotta Tetsuo, Hirano Toru, Ariizumi Takashi, Yamagishi Tetsuro, Umezu Hajime, Inagawa Shoichi, Endo Naoto
Division of Orthopedic Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
Division of Pathology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
World J Surg Oncol. 2017 May 11;15(1):100. doi: 10.1186/s12957-017-1161-0.
A solitary fibrous tumour (SFT) is an unusual neoplasm typically found in soft tissues. Although SFTs can arise in the bones, they very rarely arise in the vertebral arch. Here, we describe a case of a SFT that arose in the vertebral arch of the first lumbar (L1) spinal vertebrae and mimicked osteosarcoma.
A 49-year-old woman presented with a 2-month history of lower back pain and a lumbar region mass. Magnetic resonance imaging demonstrated a heterogeneously enhanced mass in the L1 vertebral arch. The patient received neoadjuvant chemotherapy, followed by a surgical procedure comprising an anterior spinal fusion and en bloc resection. Histologically, our initial diagnosis was osteosarcoma. The postoperative course was uneventful, and the patient received adjuvant chemotherapy. However, the tumour metastasised to the lung 5 years after the first surgery, and a second surgery was performed for lung tumour resection. The histology of the metastatic lung tumour appeared similar to that of the malignant SFT, and the specimen from the first surgery was re-examined. Immunohistochemically, the tumour was positive for STAT6. Reverse transcription-polymerase chain reaction revealed a NAB2-STAT6 fusion gene, thus confirming our final diagnosis of malignant SFT. The patient died of disease progression 8 years after the first surgery; however, there was no evidence of local recurrence.
Malignant SFT in the vertebral arch is extremely rare and very difficult to distinguish histologically an osteoid from lace-like collagen. STAT6 immunostaining is useful for distinguishing malignant SFTs from other neoplasms. Although it is difficult to completely resect a SFT arising from the spine, we demonstrated the feasibility of an en bloc resection of spinal tumours arising from posterior elements, without local recurrence.
孤立性纤维瘤（SFT）是一种罕见的肿瘤，通常发生于软组织。虽然SFT可发生于骨骼，但极少发生于椎弓。在此，我们描述一例发生于第一腰椎（L1）椎弓并酷似骨肉瘤的SFT病例。
一名49岁女性，有2个月的下背痛和腰部肿块病史。磁共振成像显示L1椎弓有一个不均匀强化的肿块。患者接受了新辅助化疗，随后进行了包括前路脊柱融合和整块切除的手术。组织学上，我们最初的诊断是骨肉瘤。术后过程顺利，患者接受了辅助化疗。然而，肿瘤在首次手术后5年转移至肺部，遂进行了肺部肿瘤切除术。转移性肺肿瘤的组织学表现与恶性SFT相似，并对首次手术的标本进行了重新检查。免疫组化显示肿瘤STAT6呈阳性。逆转录-聚合酶链反应显示存在NAB2-STAT6融合基因，从而确诊为恶性SFT。患者在首次手术后8年死于疾病进展；然而，没有局部复发的证据。
椎弓恶性SFT极为罕见，在组织学上很难将类骨质与花边状胶原区分开来。STAT6免疫染色有助于将恶性SFT与其他肿瘤区分开来。虽然完全切除起源于脊柱的SFT很困难，但我们证明了整块切除起源于后部结构的脊柱肿瘤且无局部复发的可行性。
