Looking for the Outsider

This clinical case study describes a 44 year old man presenting with fatigue, weight loss, and pathologic fractures due to severe hypercalcemia (corrected calcium: 14.5 mg/dL) and markedly elevated parathyroid hormone (PTH: 4023 pg/mL). Initial suspicion of metastatic cancer was revised after biopsy revealed brown tumors, indicative of osteitis fibrosa cystica from primary hyperparathyroidism. Imaging identified an ectopic mediastinal parathyroid mass, later confirmed as parathyroid carcinoma post resection. The case underscores the diagnostic challenges of differentiating PTH-mediated hypercalcemia from malignancy, the importance of comprehensive imaging (including sestamibi scans with chest views), and the management of parathyroid carcinoma, including surgical resection and monitoring for recurrence. The patient’s complications chronic kidney disease, nephrolithiasis, and osteoporosis highlight the multisystem impact of prolonged hyperparathyroidism.

This clinical case study describes a 44 year old man presenting with fatigue, weight loss, and pathologic fractures due to severe hypercalcemia (corrected calcium: 14.5 mg/dL) and markedly elevated parathyroid hormone (PTH: 4023 pg/mL). Initial suspicion of metastatic cancer was revised after biopsy revealed brown tumors, indicative of osteitis fibrosa cystica from primary hyperparathyroidism. Imaging identified an ectopic mediastinal parathyroid mass, later confirmed as parathyroid carcinoma post resection. The case underscores the diagnostic challenges of differentiating PTH-mediated hypercalcemia from malignancy, the importance of comprehensive imaging (including sestamibi scans with chest views), and the management of parathyroid carcinoma, including surgical resection and monitoring for recurrence. The patient’s complications chronic kidney disease, nephrolithiasis, and osteoporosis highlight the multisystem impact of prolonged hyperparathyroidism.