[Cervical macroadenoma causing hyperparathyroidism: Report of one case]. / Macroadenoma cervical palpable: Una presentación muy inusual de hiperparatiroidismo primario.

We report a 59-year-old man with a history of hypertension, recurrent renal stones and a severe hypercalcemia of 14.9 mg/dl with a serum phosphorus of 2.4 mg/dl and a serum albumin of 3.6 g/dl. Physical examination showed a 4 cm left cervical nodule, consistent with the diagnosis of thyroid nodule. Parathyroid hormone (PTH) levels were 844 pg/mL (normal 15-65 pg/ml) and a cervical ultrasound examination disclosed a solid nodule in the lower left lobe of 40 x 30 x 25 mm, adjacent to the thyroid parenchyma. Abdominal ultrasound revealed bilateral renal stones. Parathyroid scintigraphy showed a high uptake of the left lower parathyroid mass and a bone densitometry showed bone density t scores of -1.2 in the spine, -2.0 in the right femoral neck and -3.5 in the distal radius. A review of his medical record revealed the presence of hypercalcemia for at least 4 years. He was admitted for hydration and administration of 4 mg zoledronic acid iv. At 24 hours, serum calcium dropped to 11.0 mg/dl, and a left thyroid lobectomy was performed including the lower left parathyroid gland. The pathology report showed a 22.6 g parathyroid adenoma. Intraoperatory PTH descended > 50%, consistent with successful parathyroidectomy. At 7 days after surgery serum calcium was 8.8 mg/dl, phosphorus 2.1 mg/dl, alkaline phosphatase 166 U/L, albumin 3.9 g/dL, PTH 230 pg/ml and 25-OH vitamin D 12.4 ng/ml. This finding was interpreted as secondary hyperparathyroidism due to vitamin D deficiency and "hungry bone", being less likely the presence of residual or metastatic parathyroid tissue. A cholecalciferol load was administered, with significant descent of PTH.