Vol. 3, Issue 1, Part A (2021)

Background: Pheochromocytomas are rare neuroendocrine catecholamine-producing tumors that may arise from the adrenal medulla (PHEO) or from extra-adrenal paraganglionic tissues (PGLs). The diagnosis of PHEO/PGLs may be challenging and depends mainly on the biochemical and radiological investigations. Methods: Retrospective review of 26 patients who had histologically proven PHEO/PGLs in our surgical department from 2011 to 2021. These patients were compared to another set of 26 patients who had adrenalectomy for other adrenal pathologies. The plasma and 24-hour urinary levels of metanephrines (metanephrine and normetanephrine) were evaluated in both groups to detect the sensitivity and specificity of metanephrines. Additionally, these levels were correlated with the tumor size using SPSS 25 program. Results: 57.7% of the patients (15) were females and 42.3% (11) were males. The mean age of the patients was 56.32 ± 17.38 years of age. After exclusion of the 2 hormonally silent cases, the sensitivity and specificity of the plasma metanephrines tests were about 95.8% and 98%, respectively. On the other hand, the sensitivity and specificity for 24-hour urinary metanephrines were about 83.3% and 98%, respectively. The relationship between the tumor diameter and the summed plasma metanephrines concentrations was relatively strong (r = 0.472, P Ë‚ 0.05), while the relation between the tumor diameter and summed 24-hour Urinary metanephrine was potentially strong (r = 0. 354, P= 0. 083). Conclusion: The test for the plasma/24-hour urinary metanephrines is now considered the best diagnostic tool for investigating PHEO/PGLs. Metanephrines levels can help to predict the tumor size and assist in decision making.