Double Parathyroid Adenoma Presenting as One Mass: A Case Report

Area of Science:

• Endocrinology
• Surgical Pathology

Background:

• Primary hyperparathyroidism (PHPT) is a common endocrine disorder, typically caused by a single parathyroid adenoma.
• This report details a unique case of a double parathyroid adenoma mimicking a solitary mass.

Observation:

• A 56-year-old female presented with symptoms of PHPT, including fatigue, bone pain, and palpitations.
• Investigations revealed elevated parathyroid hormone (PTH) and calcium levels, with imaging showing two coalesced adenomas.
• Surgical excision of the large adenoma (1.483g) resulted in a 71.6% decrease in intraoperative PTH (IOPTH).

Findings:

• The excised double adenoma was the largest reported in Northern Europe and the first to present as a single mass in the region.
• Post-surgery, the patient initially improved, but later exhibited a normocalcemic elevated parathyroid hormone (NCePTH) phenomenon.
• The IOPTH drop exceeded the 50% threshold, yet NCePTH emerged weeks later, indicating it does not necessarily signify surgical failure.

Implications:

• Double parathyroid adenomas pose a higher risk of recurrent PHPT compared to solitary adenomas.
• Extended and meticulous post-operative monitoring is crucial for patients with double adenomas.
• The NCePTH phenomenon warrants further investigation and understanding in the context of parathyroid surgery outcomes.