Atypical pediatric presentation of hyperparathyroidism: CDC73 gene mutation and parathyroid carcinoma

Parathyroid carcinoma is the rarest etiological cause of primary hyperparathyroidism and is exceedingly rare in the pediatric population. Clinical manifestations include severe hypercalcemia, pathological fractures, and bone pain. Diagnosis is typically established through surgical intervention and histopathological examination; however, genetic analyses can also support the diagnosis.

A 10-year-10-month-old female presented with fatigue, leg pain, and a pathological fracture in her left forearm. Laboratory tests revealed hypercalcemia, hypophosphatemic hypercalcemia, and hyperparathyroidism. Imaging studies identified a 17 mm hypervascular hypoechoic lesion in the left paratracheal area. Surgical intervention included left inferior and superior parathyroidectomy and left thyroidectomy. Histopathology showed atypical parathyroid neoplasia and thyroid hyperplasia. Genetic testing revealed a pathogenic CDC73 mutation (p.E48*, c.142G>T). The patient is under regular follow-up for hyperparathyroidism-jaw tumor syndrome (HPT-JT) and parathyroid carcinoma.

This case highlights the importance of early genetic testing in pediatric primary hyperparathyroidism (PHP), particularly for detecting CDC73 gene mutations associated with hyperparathyroidism-jaw tumor syndrome (HPT-JT). Early diagnosis allows for timely intervention, surgical planning, and long-term surveillance to manage potential complications such as parathyroid carcinoma and ossifying fibromas.