Single Photon Emission Computed Tomography/Computed Tomography Detects a Second Ignored Intrathyroidal Parathyroid Adenoma.

The primary hyperparathyroidism (PHPT) is a result of high levels of parathyroid hormone and serum calcium, the most frequent cause is a solitary parathyroid adenoma. Double parathyroid adenoma is <5% of the PHPT. Intrathyroidal parathyroid adenoma (IPA) occurs< 3.2%. We present a case of 58-year-old female with persistent primary hyperparathyroidism due to a second undetected IPA, suspected by ultrasound and confirmed by 99mTc sestamibi single-photon emission computed tomography/computed tomography.