A Case Report of Intrathyroid Parathyroid Adenoma

Intrathyroid parathyroid adenoma as a cause of hypercalcemic crisis presents a diagnostic and therapeutic challenge, since it is uncommon and should be thoroughly differentiated from a thyroid nodule.

Herein, we report a case of a 71-year-old woman, with a history of nephrolithiasis, who presented with asthenia, vomiting and a right flank pain radiating to the right lower quadrant. Laboratory evaluation revealed severe hypercalcemia, hypophosphatemia and an elevated parathyroid hormone (PTH) level.

An ultrasonography of the neck did not detect any parathyroid adenoma, but revealed a hypoechoic nodule located within the left lobe of the thyroid. Although the intrathyroid location is difficult to appreciate,99m Technetium (Tc)-sestamibi scan revealed a partial radiotracer uptake located within the thyroid nodule.

Then,radiological features were consistent with an intrathyroid parathyroid adenoma. The patient’s parathyroid crisis was managed by intravenous hydration, furosemide and biphosphonate treatment.

After improvement of calcium level, hemithyroidectomy was performed. Pathological analysis was consistent with the diagnosis of intrathyroid parathyroid adenoma. The patient was asymptomatic and serum calcium and PTH levels remained within normal limits.

Even rare, intrathyroid parathyroid adenomas should be suspected in patients with parathyroid crisis. Multidisplinary management is recommended for accurate diagnosis and appropriate treatment.