METHODS: We present a case of PILA arising in the distal femoral epiphysis of a 50-year-old female patient. It started as a relentless pain in her left knee. A plain radiography revealed a radiolucent area in the left internal femoral condyle. Computerized tomography revealed a 1-cm lytic lesion with a sclerotic rim. Magnetic resonance images showed a significant bone marrow edema signal focused on a 1-cm subchondral lesion suggestive of an intraarticular osteoid osteoma. Histologically, the tumor contained vascular channels covered by a single endothelial layer with intraluminal papillary endothelial structures lined with hobnail cells. Immunohistochemically, the cells were positive for ERG, CD31, and D2-40. The tumor underwent cryoablation and 6 months later, after local recurrence or tumor persistence, a wide tumor resection was referred. After 7 years of follow-up, the patient displayed neither local recurrence nor distant metastases.
CONCLUSIONS: Primary intraosseous PILAs are exceedingly rare tumors that should be considered in the differential diagnosis of vascular bone tumors.
方法:我们介绍了一例50岁女性患者股骨远端骨phy中出现PILA的病例。它开始于她的左膝盖无情的疼痛。X线平片显示左股骨内髁有射线可透区域。计算机断层扫描显示1厘米的溶解性病变,带有硬化边缘。磁共振图像显示明显的骨髓水肿信号集中在1厘米的软骨下病变上,提示关节内骨样骨瘤。组织学上,肿瘤包含由单个内皮层覆盖的血管通道,管腔内乳头状内皮结构衬有hobnail细胞。免疫组织化学,细胞ERG呈阳性,CD31和D2-40。肿瘤进行冷冻消融,6个月后,在局部复发或肿瘤持续存在后,进行了广泛的肿瘤切除。经过7年的随访,患者既无局部复发也无远处转移.
结论:原发性骨内PILA是非常罕见的肿瘤,在血管骨肿瘤的鉴别诊断中应考虑。