Primary hyperparathyroidism due to cystic adenoma

Parathyroid cystic adenomas are often misdiagnosed as thyroid cysts and routine preoperative diagnostic tools, such as ultrasonography (US) or sestamibi scans, cannot clearly distinguish between these entities.

Kawashima et al. present the case of a 67-year-old hypercalcemic woman with a cervical cystic lesion who had negative sestamibi scan results. Her laboratory data indicated primary hyperparathyroidism. The cervical US and computed tomography scans revealed a large and vertically long cystic mass. For preoperative definitive diagnosis, they carried out a parathyroid fine-needle aspiration (FNA) and PTH assay (PTH–FNA) of liquid aspirated from the cyst. Based on the results of this test the patient was diagnosed with primary hyperparathyroidism due to a cystic mass. She underwent a left upper parathyroidectomy and her serum calcium and intact PTH concentration immediately decreased to normal levels.

This report describes the usefulness of PTH–FNA for localizing and differentiating an atypical functional parathyroid lesion from nonfunctional tissue in primary hyperparathyroidism. They suggest that if not contraindicated, PTH–FNA could be helpful in the differential diagnosis of equivocal cervical tumors.

Read full Case at Kawashima et al. (2014), Endocrinology, Diabetes & Metabolism Case Reports, DOI: 10.1530/EDM-14-0086