A rare case of intrathyroidal cystic parathyroid adenoma

Cystic parathyroid adenomas are rare causes of primary hyperparathyroidism, representing about 1–2% of cases.1 Even rarer are cystic ectopic intrathyroidal parathyroid adenomas, with only eight cases in reported literature.1 Due to its rarity, it is rarely considered as a differential diagnosis on imaging, fine needle aspiration and macroscopic examination of the thyroid. We report a case for a 79-year-old female patient who presented with primary hyperparathyroidism and left thyroid nodule. The patient initially underwent fine needle aspiration for the nodule which was designated a Bethesda Category 3 result. Subsequently the patient underwent parathyroid exploration as well as a total thyroidectomy revealing a multilocular cystic lesion in keeping with an intrathyroidal parathyroid adenoma. This case highlights the characteristic findings and diagnostic considerations. Reference 1. Chen J, Ma Z, Yu J. Diagnostic pitfalls in a cystic ectopic intrathyroidal parathyroid adenoma mimicking a nodular goiter: A care-compliant case report. Medicine (Baltimore) 2019; 98: e14351.