Shao Mingyan, Xu Rong, Qi Wanling, Luo Zhehuang, Liao Fengxiang, Fan Sisi
Department of Nuclear Medicine, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, China.
Department of Pathology, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, China.
Front Oncol. 2024 Jan 9;13:1309123. doi: 10.3389/fonc.2023.1309123. eCollection 2023.
Synovial sarcoma is a malignant tumor of mesenchymal origin with a high degree of malignancy and easy metastasis. It mostly occurs in distal extremities or adjacent joints, and it is most common in deep knee joint. Primary sacral synovial sarcoma (PSSS) is extremely rare. The PET/CT imaging findings of a case of monophasic PSSS were reported. The clinical, imaging, and pathological data were summarized, and the literature was reviewed.
A 67-year-old female patient presented with sacrococcygeal pain without obvious causes on 16 September 2022, with occasional pain at night, as well as aggravated pain during hip flexion and long-distance walking, which could be slightly relieved with rest, without special treatment. For further treatment before 1 month to Jiangxi Provincial People's Hospital, after admission, laboratory tests were negative. Non-contrast CT scan showed expansive bone destruction in the S1-3 vertebrae with soft tissue density of about 58 mm × 46 mm × 52 mm. The boundary was clear, necrosis was visible within the vertebrae, and the boundary between the mass and the anterior sacral blood vessels and rectum was unclear. Non-contrast MRI scan showed mixed signals in lumbosacral masses, with equal signals in T1 and uneven and slightly higher signals in T2. Cystic degeneration and necrosis were visible, with multiple compartments in the lumbosacral masses. MRI enhancement showed uneven enhancement of lumbosacral mass with multiple compartments and no enhanced cystic lesion. The left sacral alar bone is destroyed, as shown by large flaky uneven strengthening. PET/CT showed that S1-3 vertebral body and left sacral alar bone were destroyed and soft tissue shadow formed, invading the sacral canal and the left foramina of S1-3. FDG metabolism was significantly increased, and malignant tumor was diagnosed by PET/CT. Pathological examination: The pathological diagnosis was monophasic PSSS. After systemic chemotherapy and local radiotherapy, no significant signs of recurrence and metastasis were found on CT so far. Follow-up treatment was continued.
The incidence of PSSS is very low, its clinical and imaging manifestations lack characteristics, and the final diagnosis still needs pathology. PET/CT imaging has a certain value in the diagnosis of PSSS and has great application value in the preoperative staging, postoperative efficacy evaluation, and follow-up.
滑膜肉瘤是一种间叶源性恶性肿瘤，恶性程度高，易发生转移。多发生于四肢远端或邻近关节，以膝关节深部最为常见。原发性骶骨滑膜肉瘤（PSSS）极为罕见。本文报道1例单相型PSSS的PET/CT影像表现，总结其临床、影像及病理资料并复习相关文献。
2022年9月16日，一名67岁女性患者无明显诱因出现骶尾部疼痛，夜间偶有疼痛，髋关节屈曲及长途行走时疼痛加重，休息后可稍缓解，未进行特殊治疗。1个月前到江西省人民医院进一步诊治，入院后实验室检查均为阴性。非增强CT扫描显示S1-3椎体骨质呈膨胀性破坏，软组织密度影大小约为58 mm×46 mm×52 mm，边界清晰，椎体内可见坏死，肿块与骶前血管及直肠分界不清。非增强MRI扫描显示腰骶部肿块呈混杂信号，T1WI呈等信号，T2WI呈不均匀稍高信号，可见囊变坏死，腰骶部肿块呈多房性。MRI增强扫描显示腰骶部多房性肿块强化不均匀，囊变区无强化。左侧骶骨翼骨质破坏，呈大片状不均匀强化。PET/CT显示S1-3椎体及左侧骶骨翼骨质破坏并形成软组织影，侵犯骶管及左侧S1-3椎间孔，FDG代谢明显增高，PET/CT诊断为恶性肿瘤。病理检查：病理诊断为单相型PSSS。经全身化疗及局部放疗后，目前CT检查未见明显复发及转移征象，继续随访治疗。
PSSS发病率极低，其临床及影像表现缺乏特征性，最终诊断仍需依靠病理。PET/CT成像对PSSS的诊断具有一定价值，在术前分期、术后疗效评估及随访中具有重要应用价值。
