Multiple brown tumors caused by parathyroid adenoma identified by 18F-FDG PET/CT in a patient with thalassemia: a case report

Brown tumors are a rare bone metabolic disorder associated with primary hyperparathyroidism and can mimic metastatic cancer. However, conventional imaging techniques often pose challenges for accurate diagnosis. We present a case of multiple brown tumors associated with a parathyroid adenoma in a patient with thalassemia, which were identified using 18F-FDG PET/CT. We report a case of a 19-year-old man with thalassemia who presented with a tumor mass in the right shoulder. Imaging studies, including X-ray and MRI, suggested the possibility of myeloma, lymphoma, or metastasis. 18F-FDG PET/CT revealed diffuse skeletal lesions, multiple osteolytic bone destructions, and a mass in the right parathyroid area with increased glucose metabolism. Elevated parathyroid hormone (PTH) and serum calcium assisted in the diagnosis of a right parathyroid adenoma, which caused secondary brown tumors. The patient underwent parathyroidectomy, and pathological examination confirmed the diagnosis, and follow-up CT at 4 months post-surgery showed that the damaged bone was gradually undergoing repair. And the laboratory evaluation showed that the PTH and serum calcium were decreasing gradually or returning to normal. Multiple brown tumors caused by parathyroid adenoma is often difficult to diagnose and often misdiagnosed as primary or secondary bone tumors. When brown tumors occur as multiple osteolytic lesions throughout the body, 18F-FDG PET/CT imaging generally facilitates accurate diagnosis.