General Hospital of Ningxia Medical University, 804 Shengli Street, Xingqing District, Yinchuan, 750004, People's Republic of China.
Ningxia Medical University, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, People's Republic of China.
BMC Musculoskelet Disord. 2021 Apr 23;22(1):381. doi: 10.1186/s12891-021-04262-0.
Chondroblastoma (CB) is a rare, primary, benign bone tumor that commonly affects men aged 15-20 years. It is usually detected in the epiphysis of the long bones, such as the proximal femur, humerus, and tibia. The patella is an infrequent site. CB with secondary aneurysmal bone cyst (ABC) is extremely rare in the patella, which can be easily confused with other common bone tumors of the patella. Thus, it is necessary to make the right diagnosis to get a good outcome.
We have presented here the case of a 30-year-old man who was suffering from anterior knee pain for the past 6 months that had aggravated 2 weeks before the presentation. Osteolytic bone destruction in the patella could be detected in both his X-ray and computed tomography (CT) examinations, while the magnetic resonance imaging (MRI) detected a fluid level. Accordingly, secondary ABC was presumed. We diagnosed the condition as giant cell tumor (GCT) with secondary ABC and, accordingly, performed curettage inside the focus region with autogenous bone grafting following the patient's medical history, physical manifestations, results of physical and ancillary examinations, and the disease characteristics. However, the intraoperative and postoperative outcomes indicated that the patient's histopathology was consistent with that of typical CB, suggesting a definitive error in diagnosis. Accordingly, the patient was finally diagnosed with patella CB along with secondary ABC.
Past studies have demonstrated that the 3 commonest bone tumors affecting the patella are GCT, CB, and ABC. CB with secondary ABC can be easily misdiagnosed as GCT with secondary ABC or ABC. Performing incision biopsy or excision biopsy and conducting histological examination may be the most effective method for suspected CB with secondary ABC.
软骨母细胞瘤（CB）是一种罕见的原发性良性骨肿瘤，常见于 15-20 岁男性。它通常发生在长骨的骨骺，如股骨近端、肱骨和胫骨。髌骨是一个不常见的部位。髌骨的继发性动脉瘤样骨囊肿（ABC）非常罕见，容易与其他常见的髌骨骨肿瘤混淆。因此，正确诊断至关重要，以获得良好的治疗效果。
我们报告了一位 30 岁男性的病例，他过去 6 个月一直遭受前膝疼痛，2 周前加重。他的 X 线和计算机断层扫描（CT）均显示髌骨溶骨性骨破坏，磁共振成像（MRI）检测到液性水平。因此，推测为继发性 ABC。我们根据患者的病史、临床表现、辅助检查结果和疾病特征，诊断为伴继发性 ABC 的巨细胞瘤（GCT），并进行了病灶内刮除和自体骨移植。然而，术中及术后结果表明，患者的组织病理学与典型 CB 一致，提示明确的诊断错误。因此，该患者最终诊断为髌骨 CB 伴继发性 ABC。
既往研究表明，常见的 3 种影响髌骨的骨肿瘤是 GCT、CB 和 ABC。伴继发性 ABC 的 CB 容易误诊为 GCT 伴继发性 ABC 或 ABC。对于疑似伴继发性 ABC 的 CB，行切开活检或切除活检并进行组织学检查可能是最有效的方法。
