Zhang Jiangchao, Xiong Ge, Zheng Wei, Sun Jing
Peking University Fourth School of Clinical Medicine, Beijing, China.
Department of Hand Surgery, Beijing Jishuitan Hospital, Capital Medical University, Beijing, China.
Orthop Surg. 2025 Mar;17(3):753-761. doi: 10.1111/os.14321. Epub 2024 Dec 16.
Benign and malignant intraosseous schwannomas are rare, and primarily documented in case reports. This study aims to elucidate the differences in clinical features and imaging manifestations between these tumors. This will help clinicians identify malignant lesions at an early stage, reliable guide treatment decisions, and accurately predict outcomes.
Eighteen patients who underwent surgery and got pathological examinations in our hospital from 2012 to 2023 were retrospectively reviewed. Among them, 14 cases were found benign with 4 malignant. In the benign group, patients underwent curettage followed by bone grafting, whereas the malignant group was treated with extensive resection or amputation. Patients' demographics and radiographic features, including gender, age at diagnosis, symptom duration, tumor location, tumor margin, and the ratio of sclerotic margins were documented and compared between these tumors. All imaging was reviewed by two fellowship-trained musculoskeletal radiologists, who also quantified the sclerotic margin ratio. The intraclass correlation coefficient was used to determine inter-observer agreement. The Mann-Whitney U test was applied for continuous clinical variables, and the chi-square test or Fisher's exact test for categorical variables.
In our series, the mean age of these patients was 43.1 ± 14.0 years, six patients were male and 12 were female. Pain was the predominant preoperative symptom. The average duration from symptom onset to initial physician visit was 28.5 ± 25.3 months for benign schwannomas and 8.3 ± 4.3 months for malignant schwannomas (p = 0.012). On plain radiographs, 13 (13/14) of benign schwannomas exhibited well-defined margins of bone destruction, compared to 1 (1/4) of malignant schwannomas (p = 0.019). Furthermore, benign schwannomas had a significantly higher sclerotic margin ratio (75.5%) than malignant ones (16.7%) (p = 0.001). No statistically significant difference was found between the two groups in terms of cortical bone destruction (p = 1.0). On MRI, both tumors demonstrated intermediate to slightly hypointense signal intensity on T1-weighted images and heterogeneous high signal intensities on T2-weighted images.
Despite their rarity, benign and malignant intraosseous schwannomas should be considered in the differential diagnosis for patients presenting with painful and radiographically lytic bone lesions, especially in the mandible, sacrum, and vertebrae. The ratio of sclerotic margins, which we proposed for the first time, in combination with symptom duration and the clarity of tumor margins, provide valuable diagnostic clues for distinguishing the malignancy of the tumors.
良性和恶性骨内神经鞘瘤均较为罕见，主要通过病例报告记录。本研究旨在阐明这些肿瘤在临床特征和影像学表现上的差异。这将有助于临床医生早期识别恶性病变，可靠地指导治疗决策，并准确预测预后。
回顾性分析2012年至2023年在我院接受手术及病理检查的18例患者。其中，14例为良性，4例为恶性。良性组患者接受刮除术并植骨，而恶性组则采用广泛切除或截肢治疗。记录并比较两组患者的人口统计学和影像学特征，包括性别、诊断时年龄、症状持续时间、肿瘤位置、肿瘤边界以及硬化边界比例。所有影像学资料由两名接受过专科培训的肌肉骨骼放射科医生进行评估，他们还对硬化边界比例进行了量化。组内相关系数用于确定观察者间的一致性。连续临床变量采用Mann-Whitney U检验，分类变量采用卡方检验或Fisher精确检验。
在我们的研究系列中，这些患者的平均年龄为43.1±14.0岁，男性6例，女性12例。疼痛是主要的术前症状。良性神经鞘瘤从症状出现到首次就诊的平均时间为28.5±25.3个月，恶性神经鞘瘤为8.3±4.3个月（p = 0.012）。在X线平片上，13例（13/14）良性神经鞘瘤表现为边界清晰的骨质破坏，而恶性神经鞘瘤仅有1例（1/4）如此（p = 0.019）。此外，良性神经鞘瘤的硬化边界比例（75.5%）显著高于恶性神经鞘瘤（16.7%）（p = 0.001）。两组在皮质骨破坏方面无统计学显著差异（p = 1.0）。在MRI上，两种肿瘤在T1加权图像上均表现为中等至轻度低信号强度，在T2加权图像上表现为不均匀高信号强度。
尽管良性和恶性骨内神经鞘瘤罕见，但对于出现疼痛性和影像学上溶骨性骨病变的患者，尤其是在下颌骨、骶骨和椎骨，鉴别诊断时应考虑到它们。我们首次提出的硬化边界比例，结合症状持续时间和肿瘤边界的清晰度，为区分肿瘤的恶性程度提供了有价值的诊断线索。
