[Solitary mediastinal fibrous tumor complicated by hypoglycemic crises (Doege-Potter syndrome)]. / Solitarnaya fibroznaya opukhol' sredosteniya, oslozhnennaya gipoglikemicheskimi krizami (sindrom Doge­Pottera).

Diagnostic and treatment algorithms for large mediastinal tumors are clear. However, long-term results are not always good. They largely depend on early diagnosis and morphological structure of tumor. Neoplasms may be asymptomatic for a long time, especially in case of slow growth. These tumors are usually diagnosed as soon as complications occur (for example, compression syndrome). Routine X-ray screening is rarer situation. Paraneoplastic syndromes are rare, and some ones are casuistic and unknown to surgical community. We describe the diagnosis and treatment of a patient with giant solitary mediastinal tumor complicated by hypoglycemic crises (Doege-Potter syndrome). This complication was life-threatening and required a multidisciplinary approach. Aggressive surgical approach cured the patient and returned her to normal lifestyle. The proposed algorithm for perioperative drug therapy was effective and deserves attention. This report will be useful for surgeons, oncologists, anesthesiologists, intensive care specialists and endocrinologists.

[Primary hyperparathyroidism and vitamin D deficiency].

Primary hyperparathyroidism (PHPT) is the third most common endocrine disease after diabetes mellitus and thyroid pathology. Recent epidemiological and experimental data have shown that long-term maintenance of low vitamin D levels in the blood can lead to the development of hyperplastic processes in the cells of the parathyroid glands, followed by autonomous production of parathyroid hormone. In PHPT vitamin D insufficiency or deficiency according to various sources occurs with a frequency of 5377% of cases. The literature review indicates more severe disease in patients with concomitant vitamin D deficiency. The expediency of preoperative assessment of vitamin D levels in all patients with PHPT in order to minimize the risk of hypocalcemia after parathyroidectomy is discussed. This article presents the relationship between vitamin D deficiency and PHPT, as well as possible methods for correcting vitamin D deficiency in PHPT. Molecular and cellular mechanisms of the occurrence of pathological processes in the parathyroid glands under conditions of low vitamin D levels are presented.

[Differential diagnosis of normocalcemic hyperparathyroidism and idiopathic hypercalciuria on the example of clinical case].

Idiopathic hypercalciuria is a heterogeneous generalized disorder caused by various defects in calcium transport and increased urinary calcium excretion. The main etiopathogenetic factors are violations of vitamin D metabolism, changes in the sensitivity of calcitriol receptors and violations of the processes of calcium reabsorption in the proximal tubules and in the ascending knee of the Henle loop. This article presents a clinical observation of patient with idiopathic hypercalciuria, initially high levels of parathyroid hormone (PTH) in the absence of hyperparathyroidism. Therapy with thiazide diuretics allowed to achieve normalization of daily urinary calcium excretion and reducing PTH. Despite the low prevalence of idiopathic hypercalciuria, differential diagnosis of this metabolic disorder should be carried out with mandatory consideration of clinical and laboratory data, as well as with diseases that may cause increased PTH production.