Pilar Pérez Reyes, Ángel Rebollo Román, María Rosa Alhambra Expósito, Jose Carlos Padillo Cuenca, Carmen Serrano Laguna, Paloma Moreno Moreno, Juan Manuel Rodríguez Camacho, María Ángeles Gálvez Moreno
Hypoparathyroidism is the most common complication after total thyroidectomy and may be particularly severe in pediatric Graves' disease. We report the case of a 14-year-old boy with Graves' disease who developed profound postoperative hypocalcemia after total thyroidectomy, with serum calcium 5.9 mg/dL, ionized calcium 0.83 mmol/L, and undetectable parathyroid hormone. Despite intravenous and high-dose oral calcium plus calcitriol, biochemical control remained poor, with persistent hypocalcemia, hyperphosphatemia, and ongoing treatment requirements after 16 days. Off-label subcutaneous palopegteriparatide, a long-acting PTH(1-34) prodrug, was started after multidisciplinary assessment and informed family consent. Serum calcium improved within 48 h, intravenous calcium was stopped after 5 days, and calcitriol, sevelamer, and calcium acetate were discontinued within 11 days. Treatment was well tolerated. This case suggests that early PTH replacement may be a useful rescue strategy in selected children with severe refractory post-thyroidectomy hypocalcemia.