RESUMO
Neonatal primary hyperparathyroidism [NPHP] is a rare disease characterized by marked hypercalcemia, diffuse parathyroid hyperplasia and skeletal demineralization. These patients have symptoms of chronic hypercalcemia such as failure to thrive, irritability, abdominal pain and anorexia. It is often fatal unless parathyroidectomy is performed. Treatment with drugs usually is inadequate and often results in chronic hypercalcemia and death. A 10-day-old, 2.9 kg male newborn was hospitalized for anorexia, poor feeding, cyanosis, hypotonia, lethargy and severe dehydration. Diagnosis of severe hypercalcemia due to primary hyperparathyroidism was established and surgical approach selected because of failure of medical therapy to control hypercalcemia. The baby was successfully treated by total parathyroidectomy with autotransplantation. Although neonatal primary hyperparathyroidism [NPHP] is a rare disease, it must be considered for differential diagnosis in neonates with severe hypercalcemia. Early diagnosis and total parathyroidectomy with autotransplantation can be life-saving