严重甲状旁腺功能亢进症的骨骼并发症之一是棕色瘤，由修复性肉芽组织和增生的纤维组织以及含铁血黄素沉积所组成。多发性棕色瘤是原发性甲状旁腺功能亢进症极为罕见的并发症。一名41岁女性患者出现左膝疼痛症状。放射学检查显示双下肢股骨以及左侧胫骨近端存在多发性囊性病变，并且额外的摄影显示左侧肱骨和尺骨也存在多发性囊性病变。核磁共振成像（MRI）显示双侧股骨、左侧胫骨和髂骨存在多发性囊性病变。实验室检查显示高血钙（经血清白蛋白校正后的钙水平为13.9 mg/dl）、低血磷酸盐（磷酸盐水平为1.6 mg/dl）、碱性磷酸酶升高（614 U/l）以及明显升高的甲状旁腺激素（PTH）水平（1,070 pg/ml；正常范围为10-65 ng/l）。99mTc-六可疑亚甲氧基异丁基异腙扫描显示左侧上甲状旁腺腺体存在示踪物积累，与甲状旁腺瘤一致。虽然计划切除甲状旁腺瘤，但患者在肿瘤切除前患有甲状旁腺出血。甲状旁腺出血后，血清钙和PTH水平暂时正常化。诊断2年后PTH水平重新升高，患者接受了左侧上甲状旁腺切除术。肿瘤切除后1年，患者没有出现任何症状，MRI显示囊性骨病灶缩小。本报告强调在多发性骨病变患者中考虑甲状旁腺功能亢进症作为鉴别诊断的重要性。版权所有2023年，国际抗癌研究学会。

Brown tumor, a skeletal complication of severe hyperparathyroidism, comprises reparative granulation tissue and proliferating fibrous tissue with hemosiderin deposition. Multiple brown tumors are extremely rare complications of primary hyperparathyroidism.A 41-year-old woman presented with pain in the left knee. Radiography showed multiple cystic lesions in both femurs and the left proximal tibia, and additional radiography showed multiple cystic lesions in the left humerus and ulna. Magnetic resonance imaging (MRI) revealed multiple cystic lesions in the bilateral femurs, left proximal tibia, and ilium. Laboratory tests revealed hypercalcemia (albumin-corrected calcium level, 13.9 mg/dl), hypophosphatemia (phosphate level, 1.6 mg/dl), elevated level of alkaline phosphatase level (614 U/l), and markedly elevated parathyroid hormone (PTH) level (1,070 pg/ml; normal range=10-65 ng/l). 99mTc-hexakis-2-methoxyisobutyl-isonitrile scintigraphy revealed tracer accumulation in the left upper parathyroid gland, which was consistent with parathyroid tumor. Although resection of the parathyroid tumor was planned, the patient developed parathyroid apoplexy before tumor excision. After the parathyroid apoplexy, serum calcium and PTH levels temporarily normalized. Resurgence of the PTH level was observed 2 years after the diagnosis, and the patient underwent left upper parathyroidectomy. One year after the tumor excision, the patient had no symptoms, and MRI showed shrinkage of the cystic bone lesions.This report emphasizes the importance of considering hyperparathy-roidism as a differential diagnosis for patients with multiple bone lesions.Copyright 2023, International Institute of Anticancer Research.