Case report: lady with bone pains for 5 years-parathyroid carcinoma

Parathyroid cancer is a rare cause of primary hyperparathyroidism. It presents a diagnostic and therapeutic challenge that may not be recognized preoperatively, and is often not conclusively identified during the operation. We present the case of a lady with backache and hypercalcemia, but with inadequate work-up for her condition for several years.

A middle aged lady of Asian descent presented with backache. Initial work up revealed mild hypercalcemia, negative work up for multiple myeloma, negative sestamibi scan for parathyroid pathology. A phenomenally elevated parathormone (PTH) level-2105 pg/mL (16-87 pg/mL), and rising serum calcium, 15.1 mg/dL, (8.6-10.5 mg/dL), ordered years later prompted a repeat sestamibi scan and ultrasonography of neck. Based on these investigations, a diagnosis of primary hyperparathyroidism, with high suspicion of parathyroid cancer was made. The patient underwent surgical tumour resection, with subsequent histopathological confirmation of diagnosis.

In the setting of hypercalcemia, PTH level assessment is a must. This helps to differentiate between the parathyroid dependant and independent causes of high serum calcium, thereby encouraging a comprehensive pathway to the work up of the cause of hypercalcemia. The parathyroid cancer is a very rare cause of hypercalcemia, which needs to be considered in the differentials of primary hyperparathyroidism, particularly in the setting of high PTH levels.