[Case of clinically "aggressive" course of primary hyperparathyroidism, algorithm of differential diagnosis].

Primary hyperparathyroidism (PHPT) is a significant endocrine disease caused by increased production of parathyroid hormone (PTH) by altered parathyroid glands and violation of the mechanisms of regulation of serum calcium concentrations. These changes can lead to nephrolithiasis, osteoporosis, erosive and ulcerative lesions of the gastrointestinal tract, a number of less specific symptoms (nausea, vomiting, weakness, fatigue, etc.). Etiologically, in more than 85% of cases, PHPT is a consequence of sporadic solitary adenoma or hyperplasia parathyroid glands, however, in 1-3% of cases, the cause is carcinoma of parathyroid glands , including as part of various genetic syndromes. The importance of timely examination for PHPT of patients with characteristic clinical manifestations of this disease and - with an aggressive course - alertness towards carcinomas of parathyroid glands was noted. At the same time, the severity of the clinical picture and even the presence of suspicious signs characteristic of hereditary forms of carcinomas of parathyroid glands are not always a consequence of the malignant process. We present a description of a young patient with a severe course of PHPT, multiple fractures and a voluminous tumor of the upper jaw, developed as a result of a typical adenoma of parathyroid glands. Additionally, the algorithm of pre- and postoperative differential diagnosis for such patients is highlighted.