Remission of Primary Hyperparathyroidism Following Fine-Needle Aspiration Biopsy: A Case Report and Review of the Literature

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.

Remission of primary hyperparathyroidism after fine needle aspiration of a parathyroid nodule mistaken for a thyroid nodule

Primary hyperparathyroidism (PHPT) is an endocrine disorder characterized by hypercalcaemia and elevated or inappropriately normal concentrations of parathyroid hormone. Remission of PHPT caused by infarction or hemorrhage of a parathyroid adenoma rarely occurs, either spontaneously or induced, not always leading to a definitive cure. We report a case of 72-year-old women with primary hyperparathyroidism who underwent fine-needle aspiration cytology (FNAC) of a parathyroid adenoma mistaken for a thyroid nodule followed by normalization of parathyroid hormone (PTH) and serum calcium levels. Parathyroid origin was confirmed by immunohistochemistry. PTH levels began to rise at 4 months after FNAC demonstrating recurrence of the PHPT. This report shows that FNAC induced hemorrhage may cause remission of PHPT. Nevertheless, patient´s levels of PTH and serum calcium should be monitored, as remission may only be transitory.

Transient remission of hyperparathyroidism after fine-needle aspiration biopsy

Primary hyperparathyroidism (PHPT) is the unregulated overproduction of parathyroid hormone (PTH), resulting in abnormal calcium homeostasis. PHPT is most commonly caused by a single adenoma of the parathyroid gland, which can have an intrathyroid location in rare cases. The measurement of intact PTH in the washout fluid obtained by ultrasound (US)-guided fineneedle aspiration (FNA) can be useful in clarifying the aetiology of these lesions. This study presented a 48-year-old man with a background history of symptomatic renal stone disease who was diagnosed with PHPT and referred to our Endocrinology department. A neck US revealed a thyroid nodule with a size of 21 mm in the right lobe. The patient underwent US-guided FNA of the lesion. The measurement of PTH in the washout fluid was significantly elevated. Following the procedure, he reported neck pain and noticed distal paraesthesias in the upper limbs. Blood test results showed significant hypocalcaemia and supplementation with calcium and calcitriol was started. The patient was closely monitored. Recurrence of hypercalcaemia was later observed, and the patient was submitted to surgery. We present a case of FNAinduced transitory remission of PHPT in a patient with an intrathyroid parathyroid adenoma. We conjecture that intra-nodular haemorrhage might have occurred, which temporarily affected the viability of the autonomous parathyroid tissue. A few similar cases of spontaneous or induced remission of PHPT after FNA have been previously described in the literature. This remission can be transitory or permanent, depending on the degree of cellular damage thus follow-up of these patients is recommended.