Autoinfarction of the Parathyroid Gland: An Unusual Presentation of Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is commonly caused by a parathyroid adenoma and typically presents with hypercalcemia and elevated parathyroid hormone (PTH) levels. Spontaneous infarction of parathyroid adenoma is a rare phenomenon that can lead to spontaneous resolution of hypercalcemia.

We report the case of a 48-year-old male with a history of PHPT diagnosed 7 years prior and was lost to follow up, who presented with left-sided facial and finger paresthesia. Initial labs revealed low ionized calcium with a normal PTH level. Imaging identified a heterogeneous mass adjacent to the left thyroid lobe. Biopsy confirmed infarcted parathyroid adenoma. The patient's prior PHPT had spontaneously resolved, but he now presented with symptomatic hypocalcemia likely due to adenoma infarction.

Spontaneous infarction of a parathyroid adenoma is an uncommon cause of remission in PHPT. While transient remission of hypercalcemia has been documented, long-term outcomes remain variable. Our case is unusual as the patient presented with symptomatic hypocalcemia years after initial diagnosis.

Autoinfarction of parathyroid adenomas can result in spontaneous remission of PHPT but may also lead to unexpected complications such as hypocalcemia. Ongoing follow-up is essential to monitor both recurrence of hypercalcemia and the development of hypocalcemia.