[Chromogranin A in diagnosis of pheochromocytoma (comparative analysis)].

AIM: To study the prognostic value of determining Chromogranin A blood level in the diagnosis of PHEO. MATERIALS AND METHODS: We conducted a comparative analytical study of 157 patients with suspected PHEO, statistical analysis of 24-hour urinary metanephrine and normetanephrine excretion test was performed, as well as a blood test for CrA, in groups that included patients without PHEO, with primary tumor or its recurrence, confirmed according to MSCT and/or scintigraphy with MIBG and/or the clonidine suppression test. RESULTS: The parameters of efficiency of these methods were calculated by groups and it was noted that the lowest sensitivity of the CrA determination method was observed in the group with recurrence of PHEO (43.8%), their exclusion from the entire sample didnt change specificity of the method and it remained at a high level (85.45%), though sensitivity significantly increased up to 87.1%. Sensitivity of determining 24-hour urinary metanephrine excretion also increased significantly up to 96.8%, with 98.2% of specificity. The correlation between diameter of the tumor and its secretory activity was identified: small with CrA level (rho 0.491) and strong with total level of methylated catecholamines (rho 0.765). False positive results were more often observed in patients present with other neuroendocrine tumors (37.5%), as well as those taking proton-pump inhibitors (43.75%). The sensitivity and specificity of CrA determining method in the group of patients with methanephrins elevated within gray zone appeared to be 50 and 86.1%, respectively. CONCLUSION: A blood test for CrA can be recommended as a confirmatory test for diagnosing PHEO in cases of questionable methylated catecholamines indicators or in cases of suspected relapse of PHEO. The use of the test as a first-line method is only possible if there is no possibility to study methylated catecholamines. When interpreting CrA level, it is necessary to take into account the conditions that may cause false-positive results.

[The prevalence of autoimmune endocrine diseases in vitiligo patients].

Vitiligo is a common polygenic autoimmune disease in which the foci of depigmentation are formed on the skin and/or mucous membranes as a result of the death of melanocytes. There are several hypotheses for the pathogenesis of the disease, the leading role among them is played the autoimmune hypothesis. This review summarizes the available literature data on the prevalence and structure of comorbid endocrine autoimmune pathology in vitiligo patients. In most studies conducted in Europe, America and Asia the prevalence of autoimmune thyroid diseases (including autoimmune thyroiditis and Graves disease), diabetes mellitus and autoimmune adrenal insufficiency was higher in vitiligo patients than in the general population. The results of some studies indicate a frequent association of vitiligo with autoimmune polyglandular syndromes. In the structure of comorbid pathology the highest prevalence was in autoimmune thyroid diseases. A number of studies have established a higher prevalence of autoimmune endocrine diseases in women, as well as in nonsegmental vitiligo patients and in cases of family history of vitiligo and/or other autoimmune diseases. In addition, it was shown that the prevalence of endocrine diseases increases with increasing area of depigmentation. The data obtained justify the advisability of conducting a timely examination of vitiligo patients with the aim of early detection of comorbid diseases and the appointment of appropriate treatment. Further studies are needed to investigate the effect of the identified associations on the course of vitiligo and comorbid endocrinopathies, as well as the effectiveness of therapy and the quality of life of patients.

[Immunohistochemical study on the expression/hyperexpression of aberrant/eutopic receptors in patients with bilateral macronodular adrenal hyperplasia].

Bilateral macronodular adrenal hyperplasia (BMAH) is a rare cause of Cushing's syndrome. In this case cortisol production can be regulated by both genetic factors and various molecular mechanisms. The presence of aberrant or overexpression of eutopic receptors on the membrane of adrenal cortex may lead to activation of cAMP/PKA signaling pathways and consequently, pathological stimulation of steroidogenesis. Since proving the effectiveness of unilateral adrenalectomy in BMAH by achievement of stable remission, preoperative clinical and laboratory tests (ligand-induced tests) are no longer of relevant. Nevertheless, in the absence of normalization of the level of cortisol in the postoperative period or its recurrence, subsequent specific targeted medical options can be offered only if expression/hyperexpression predominance of one or another receptor. Their detection becomes possible using more reliable diagnostic methods such as polymerase chain reaction (PCR) and immunohistochemical studies (IHC) than clinical laboratory tests. At the moment, PCR has gained a wider application. This article summarizes data on the use of immunohistochemical study in BMAH.

[Malignant insulinoma].

According to official statistics, malignant insulinomas account for a small fraction of gastroenteropathic endocrine neoplasms, the majority of insulinomas being essentially benign tumours. This paper reports a clinical case of malignant insulin-producing neuroendocrine tumour of the pancreas tail in a 28 year-old woman. She had multiple liver metastases and organic hyperinsulinism. Results of comprehensive examination of the patient at the Endocrinological Research Centre including laboratory diagnostic data and their evaluation are presented. Her surgical treatment was accomplished in N.N. Burdenko Facultative Surgery Clinic, I.M. Sechenov Moscow Medical Academy. Treatment strategy in the post-operative period and follow-up observations are described.