[The case of late diagnosis of giant parathyroid adenoma in combination with fibrocystic osteitis and brown tumor of the upper jaw: a case report].

In this case report the authors inform about late diagnosis of giant adenoma of the parathyroid gland with primary hyperparathyroidism (PHPT) and the development of fibrocystic osteitis with a «brown» tumor of the upper jaw. The patient has been under the care endocrinologist with type 2 diabetes mellitus and multinodular goiter for 8 years.The last 5 years there was a clinical manifestation of PHPT, but the diagnosis was made by an oncologist after the detection of a «brown» tumor of the upper jaw. According to multispiral computed tomography and scintigraphy with 99mTc-MIBI, a focal lesion was found in the upper jaw on the right, lytic foci in the bones of the cranial vault, pelvis, lower extremities, ribs on the right, as well as a giant parathyroid adenoma on the right. According to the increased risk of the patient having a malignant neoplasm of the parathyroid gland, an extended surgical treatment of PHPT in the enblock volume was carried out with the achievement of remission of the PHPT. This clinical case illustrates a variant of the severe course of PHPT with the development of such a rare complication as fibrocystic osteitis and demonstrates the importance of timely diagnosis.