Аннотация:Parathyroid carcinoma (PC) is extremely rare in children and adolescent. PC ismore often sporadic, but also it could be associated with germline mutations. The clinicalfeatures 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 germlineheterozygous pathogenic variant in exon 1 of the CDC73 gene (c.70 G>T, p. Glu24Ter) isthe first to be reported in Russia. Due to the rarity of pediatric parathyroid malignancy, thediagnosis of this endocrine neoplasm remains a challenge. The main difficulties that we facedin the management of the patient were the morphological confirmation of diagnosis, multiplesurgical interventions, and disseminated PC metastases. We describe a 13-year-old girlwith delayed diagnosis of PC and subsequent local recurrence after several surgeries, whounderwent specific radiation therapy that allowed controlling hypercalcemia.