Atypical Parathyroid Adenoma with Multiple Fibrous Cystic Osteitis: A Case Report

Adenoma paratiroideo atípico con osteítis fibrosa quística múltiple: Reporte de Caso 

Abstract

Atypical parathyroid adenoma is a rare neoplasm with histological features intermediate between adenoma and carcinoma, associated with severe hypercalcemia and bone complications. It requires careful histopathological diagnosis and close monitoring due to the risk of recurrence. We present a 23-year-old woman with polydipsia, polyuria, constipation, hip pain, bilateral femoral shaft fractures, and a cervical mass. Additionally, she had hypercalcemia and elevated PTH levels. CT imaging showed multilocular exophytic lesions in the iliac bones, iliopubic and ischiopubic branches bilaterally, and in the shafts of both femurs with signs of fractures, consistent with multiple foci of fibrous cystic osteitis. A left parathyroidectomy was performed, resulting in a reduction of PTH levels, followed by open reduction and internal fixation of the femoral fractures. Pathology: parathyroid adenoma with a solid-trabecular pattern (atypical). Fibrous cystic osteitis is a rare manifestation characterized by high bone remodeling due to chronically elevated PTH levels, which can lead to pathological fractures.