Combination approach for CDC73-related parathyroid carcinoma in an adolescent female patient: a case report and literature review.

Parathyroid carcinoma (PC) is extremely rare in children and adolescent. PC is more often sporadic, but also it could be associated with germline mutations. The clinical features of primary hyperparathyroidism (PHPT) are nonspecific in children and adolescent, which delays the diagnosis for years. This case of PC in a pediatric patient, caused by germline heterozygous pathogenic variant in exon 1 of the CDC73 gene (c.70 G > T, p. Glu24Ter) is the first to be reported in Russia. Due to the rarity of pediatric parathyroid malignancy, the diagnosis of this endocrine neoplasm remains a challenge. The main difficulties that we faced in the management of the patient were the morphological confirmation of diagnosis, multiple surgical interventions, and disseminated PC metastases. We describe a 13-year-old girl with delayed diagnosis of PC and subsequent local recurrence after several surgeries, who underwent specific radiation therapy that allowed controlling hypercalcemia.