Spontaneous resolution of primary hyperparathyroidism post-biopsy-related neck haematoma

Spontaneous or fine-needle aspiration (FNA)-induced remission of primary hyperparathyroidism (PHPT) is an extremely rare phenomenon with variable outcomes. We report a 75-year-old Male who initially presented with left ureteric calculi and was found to have PHPT. Imaging studies including ultrasound neck, parathyroid sestamibi scan and computed tomography of thorax, abdomen, and pelvis failed to identify the culprit lesion and exploratory parathyroidectomy was planned. Before surgery, he underwent FNA for cytology of a right cold thyroid nodule which was complicated with a large neck haematoma and dysphagia. The cytology of the aspirated fluid was consistent with a benign cyst. One month after the procedure, serum calcium and phosphate normalised along with resolution of haematoma. He remained in biochemical remission at 1-year follow-up with the latest ultrasound of neck showing resolution of a large colloid nodule that was previously seen occupying the right thyroid lobe.