Abstract
Hyperparathyroidism-jaw tumor syndrome is a rare form of syndromic primary hyperparathyroidism. We describe a young female with a history of common precursor B acute lymphoblastic leukaemia who was diagnosed with overt primary hyperparathyroidism due to a pathogenic CDC73 variant (c.25C > T). This patient posed several challenging management aspects: the development of nephrocalcinosis, the risk for parathyroid carcinoma, and persistent hyperparathyroidism after two selective parathyroidectomies, leading to the decision to perform a total parathyroidectomy. The latter resulted in permanent complete hypoparathyroidism, with subsequent difficult medical therapy. This case report illustrates the challenge to identify the optimal treatment of parathyroid disease in the context of hyperparathyroidism-jaw tumor syndrome, balancing the risks of hyperparathyroidism and parathyroid carcinoma against the burden of permanent hypoparathyroidism at young age.