嗜铬细胞瘤 (PHEO) 是一种来自肾上腺髓质嗜铬组织的肿瘤，能够过量产生儿茶酚胺。肿瘤产生的激素增加会导致儿茶酚胺危机，对所有器官和系统产生病理影响。在嗜铬细胞瘤的初步诊断中，测定儿茶酚胺代谢物-变肾上腺素的水平非常重要。目前，在临床实践中，使用多种方法来测定这种代谢物的水平：血浆或尿液中、全部或仅游离形式、分级分析或未分级分析。比较各种方法测定变肾上腺素水平的有效性嗜铬细胞瘤的诊断。对 2007 年 11 月至 2022 年 12 月在圣彼得堡皮罗戈夫国立大学高等医疗技术诊所最初接受肾上腺肿瘤手术的患者样本进行了回顾性单中心队列研究，这些患者通过了分析在手术治疗前确定血液或尿液变肾上腺素的水平。对变肾上腺素检测结果和肿瘤大小进行评估。对1088例接受手术治疗的肾上腺肿瘤患者进行了检查，其中348例经组织学证实存在嗜铬细胞瘤。比较了四种类型的变肾上腺素测定：游离分次血浆变肾上腺素（232 名患者）、未分次每日尿变肾上腺素（431 名患者）、分次总每日尿变肾上腺素（427 名患者）和分次游离每日尿变肾上腺素（178 名患者）。游离分馏血浆甲肾上腺素的分析证明了最大的灵敏度（95.4%）。与其他分析不同的是，该分析的敏感性在小嗜铬细胞瘤（3 cm 或更小）患者组中并未降低。每日尿液中普通变肾上腺素的分析证明了最大的特异性（97.8%），而所有测试中敏感性最低（67.6%）。分次总日尿变肾上腺素的研究显示出良好的敏感性和特异性，仅略逊于最佳指标，而游离日尿变肾上腺素的分析则显示出出乎意料的低效率。血液中的变肾上腺素水平与肿瘤的大小呈正相关。根据获得的数据，初步诊断嗜铬细胞瘤的首选检测方法可以考虑测定游离血浆变肾上腺素和每日总尿的分次测定变肾上腺素，这与相关临床建议一致。发现肿瘤的大小与通过任何所描述的方法测定的变肾上腺素水平增加的严重程度相关。

Pheochromocytoma (PHEO) is a tumor from the chromaffin tissue of the adrenal medulla, capable of hyperproduction of catecholamines. The increased production of hormones by the tumor leads to catecholamine crises, which have a pathological effect on all organs and systems. In the primary diagnosis of pheochromocytomas, it is important to determine the level of the metabolite of catecholamines - metanephrines. Currently, in clinical practice, various methods are used to determine the level of this metabolite: in blood plasma or in urine, total or only free form, fractionated analysis or unfractionated.Comparison of the effectiveness of various methods for determining the level of metanephrines for the diagnosis of pheochromocytomas.A retrospective single-center cohort study was conducted on a sample of patients who were initially operated on for adrenal neoplasm at the Pirogov St. Petersburg State University High Medical Technology Clinic from November 2007 to December 2022 and who passed analysis to determine the level of blood or urine metanephrins before surgical treatment. The results of tests for metanephrine and tumor size were evaluated.1088 patients with adrenal neoplasms who underwent surgical treatment were examined, of which 348 had histologically confirmed the presence of pheochromocytoma. Four types of metanephrine assays were compared: free fractionated plasma metanephrines (232 patients), unfractionated daily urine metanephrines (431 patients), fractionated total daily urine metanephrines (427 patients) and fractionated free daily urine metanephrines (178 patients). The greatest sensitivity was demonstrated by the analysis of free fractionated plasma methanephrines (95.4%). Unlike others, the sensitivity of this analysis did not decrease in the group of patients with small pheochromocytomas (3 cm or less). The greatest specificity was demonstrated by the analysis of unfractionated metanephrines in daily urine (97.8%), with the lowest sensitivity among all tests (67.6%). The study of fractionated total daily urine metanephrins showed good results of sensitivity and specificity, only slightly inferior to the best indicators, and the analysis of free daily urine metanephrins demonstrated unexpectedly low efficiency. There is a positive correlation between the level of metanephrine in the blood and the size of the tumor.Based on the data obtained, the preferred assays for the primary diagnosis of pheochromocytoma can be considered the determination of fractionated free plasma metanephrines and fractionated total daily urine metanephrines, which is consistent with relevant clinical recommendations. It was found that the size of the tumor correlates with the severity of an increase in the level of metanephrins determined by any of the described methods.