Primary Hyperparathyroidism Mimicking Skeletal Metastasis - A Diagnostic Dilemma

Primary hyperparathyroidism (PHPT) is an intrinsic abnormality of the parathyroid glands in which there is an inappropriate secretion of parathormone (PTH), resulting in skeletal resorption and bone loss. The characteristic bony changes of fibrotic cystic lesions are called Brown's tumors. Clinical dilemmas exist due to the varied clinical presentation of hypercalcemia with multiple lytic lesions mimicking metastatic bone disease. The 99 mTc sestamibi scanning is the imaging modality of choice used for the preoperative localization of parathyroid adenomas. Surgery provides a definitive treatment, and the bony lesions resolve completely over a period of time.

We present four cases of PHPT where they presented with multiple lytic lesions and were evaluated for metastatic deposits. The diagnosis was confirmed with a biopsy. They were successfully treated by excision of the parathyroid gland. A high index of suspicion will avoid misdiagnosis and inappropriate treatment.

PHPT must be considered as a differential diagnosis for multiple osteolytic bone lesions. Diagnosis can be aided by a thorough clinical examination, including an assessment for neck swelling, and laboratory testing of serum calcium levels and PTH levels. Surgical excision of the hyperactive gland serves as the definitive treatment for this condition, with bony lesions regressing gradually over time.