[Comparison of the effectiveness of various methods for determining the level of metanephrines in the diagnosis of pheochromocytomas].

BACKGROUND: 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. AIM: Comparison of the effectiveness of various methods for determining the level of metanephrines for the diagnosis of pheochromocytomas. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Feocromocitoma: punción y drenaje percutáneo precirugía en un caso que se presentó como absceso retroperitoneal / Percutaneous puncture and drainage previous to elective surgical resection of a pheochromocytoma presenting as a retroperitoneal abscess: Report of one case

We report a 57 year-old woman with a big partially cystic adrenal pheochromocytoma presenting with high fever and abdominal pain. Based on CT scan images and before knowing urinary catecholamines level, the diagnosis of sepsis secondary to an abscessed adrenal macrotumor was done. A diagnostic percutaneous fine-needle puncture and aspiration was done and antibiotic therapy was started. One week later an open surgical drainage and installation of percutaneous drainage tubes was carried out. Both procedures were uneventful and the patient improved dramatically. Three months later a definitive excision surgery was done. After 14 months of follow up, the patient is in excellent conditions and her abdominal CT scan is normal.

Incidentaloma adrenal com elevaçäo de normetanefrinas urinárias: Caso 04/96 (MAM, RG 095.567-2, Santa Casa de Misericórdia de Belo Horizonte, MG) / Incidental adrenal masses with increase of urinary normetanephrine: Case 04/96 (MAM, RG 095.567-2, Santa Casa de Misericórdia de Belo Horizonte, MG)

O avanço tecnológico na obtençäo de imagens em medicina (ultrassonografia, tomografia computadorizada e ressonância nuclear magnética) tem proporcionado uma precisäo de detalhes cada vez maior. Por isso, a incidência de achados de massas acidentais está aumentando na mesma proporçäo, obrigando-nos a deparar com novos desafios diagnósticos e terapêuticos. O incidentaloma da adrenal apresenta-se nesta categoria, constituindo um problema diagnóstico e um dilema terapêutico. O feocromocitoma é um tumor raro, que incide em apenas 0,1 por cento dos indivíduos hipertensos e se carateriza por extrema variabilidade na sua expressäo clínica. Raramente o tumor é clinicamente silencioso, porém, frequentemente, seu diagnóstico é estabelecido somente após remoçäo de um incidentaloma adrenal ou autópsia. Neste relato de caso apresentamos uma paciente assintomática, portadora de feocromocitoma silencioso, com aumento apenas dos níveis de normetanefrinas urinárias, alertando para a importância da investigaçäo funcional destas massas encontradas incidentalmente. Os resultados alterados em apenas um dos metabólitos urinários de catecolaminas (HPLC) confirmam achados prévios, de serem estes os mais sensíveis para investigaçäo dos incidentalomas adrenais na detecçäo de feocromocitomas.