RESUMEN
INTRODUCTION: The hypercalcemia is infrequent in pediatrics, its clinical is diverse, and its etiology is determined by age. Among the dependent causes of parathormone (PHT) is the hyperthyroidism, state of hypersecretion of PHT by parathyroid glands (PG). The primary hyperparathyroidism (PHPT) is rare in children, there are 200 reported cases. In older children, the causes for PHPT correspond to parathyroid adenoma, multiglandular disease and parathyroid carcinoma. OBJECTIVE: Report a case of an 11 years old male adolescent. He presents three months symptoms of constipation, anorexia, vomiting and weight loss. Urgent consultation due to an increase of his symptoms, in exams stand out: calcemia 16.67 mg/dl (NV 8.8-10.8 mg/dl), phosphatemia 2.21 mg/dl (NV 4.5-5.5 mg/dl), parathormone (PHT) 308.7 pg/ml (NV 15-68.3 pg/ml), calciuria/creatininuria 0.56 (NV < 0.2). He was hospitalized to manage his severe hypercalcemia, it was indicated hyperhydration, monopotassium phosphate, intravenous hydrocortisone and furosemide. In his study was performed a cervical ultrasound which showed a solid node in the right parathyroid gland, hypoechogenic and scintigram parathyroid compatible with right superior parathyroid adenoma. In the waiting for surgery was necessary the administration of intravenous pamidronate. In the post-operatory, he evolved with hipocalcemia that was corrected with intravenous calcium carbonate, overlapping to oral calcium and calcitriol. CONCLUSION: The PHPT is a pathology of low prevalence in pediatrics, one hundred times less than adults. In the adolescent, the most frequent cause is the parathyroid adenoma. It should be considered as a differential diagnosis in cases of symptomatic hypercalcemia in this age group