Intrathymic parathyroid adenoma

Intrathymic parathyroid adenoma is a rare cause of persistent primary hyperparathyroidism. We encountered a case of intrathymic parathyroid adenoma, detected by computed tomographic scan and confirmed by Technetium-99 (Tc-99) Sestamibi scan and histology. The surgical approach included a median sternotomy and a large intrathymic parathyroid adenoma was identified and excised through the sternotomy. In this case, Tc-99 Sestamibi scan successfully localized a persistant abnormal tracer uptake in the mediastinum suggestive of mediastinal parathyroid adenoma. Although not recommended for routine preoperative evaluation, scintigraphy can be useful in the preoperative localization of ectopic parathyroid adenomas.