Abstract：
Paget osteosarcoma is a rare but serious complication of Paget disease requiring immediate management before further malignant transformation. This case report examines the progression of a previously reported case of Paget disease with atypical pseudotumor manifestation, mimicking osteosarcoma over a 21-year time lapse. After presenting with substantial pain and elevated alkaline phosphatase levels, imaging proved extensive bony expansion of the lesion with high-grade trabecular and cortical thickening and extraosseous soft-tissue extension, prompting the need for biopsy to rule out Paget sarcoma. The atypical features of the pseudotumor\'s development helps distinguish key radiographic and clinical criteria for malignant development.
摘要：
Paget骨肉瘤是Paget病的一种罕见但严重的并发症，需要在进一步的恶性转化之前立即治疗。该病例报告检查了先前报道的具有非典型假瘤表现的Paget病病例的进展。模仿骨肉瘤超过21年的时间间隔。在出现严重疼痛和碱性磷酸酶水平升高后，影像学检查证实病变广泛的骨扩张，伴有高度小梁和皮质增厚以及骨外软组织扩张，提示需要进行活检以排除Paget肉瘤。假瘤发展的非典型特征有助于区分恶性发展的关键影像学和临床标准。
