{Reference Type}: Case Reports {Title}: Osteolytic Lesions (Brown Tumors) of Primary Hyperparathyroidism: A Report of Two Cases. {Author}: Alrotoie AM;Aljohani AA;Alrehaili R;Alharbi M;Alalawi YM; {Journal}: Cureus {Volume}: 16 {Issue}: 6 {Year}: 2024 Jun 暂无{DOI}: 10.7759/cureus.61708 {Abstract}: Primary hyperparathyroidism is characterized by excessive production of parathyroid hormone. As the condition progresses, bone loss primarily occurs due to resorption. A complication of this condition is the formation of fibrotic and cystic changes in the bone, known as brown tumors. These lesions occur in areas of significant bone resorption, where fibrovascular tissue and giant cells replace bone tissue, often accompanied by hemorrhage and hemosiderin deposits. These brown lesions are rare, with an occurrence rate ranging from 1.5% to 4.5%. We present two cases of middle-aged women who had presentations consistent with hyperparathyroidism and presented with complications such as bone pain and numbness. Both underwent parathyroidectomy to manage the cause and recovered after the surgery. These cases emphasize the importance of recognizing primary hyperparathyroidism as a potential cause of abnormal lesions and highlight the diverse presentations associated with this condition.