Endocrine Abstracts

Introduction: Phaeochromocytomas (PHEO) are diagnosed with classic findings and symptoms but biochemical confirmation must be made. Either urinary or plasma chatecholamines and metanephrines can be used for biochemical evaluation. Normal values rule out the diagnosis, whereas fourfold increase above the upper limit of normal confirm the diagnosis. But value of borderline or less than fourfold elevations in the diagnosis is not clear. We aimed to determine the urinary fractionated metanephrine and catecholamine levels in patients with PHEO.

Material and methods: Thirteen patients with final diagnosis of PHEO (PHEO group) and ten patients (non-PHEO group) who underwent to adrenalectomy and finally diagnosed as benign neoplasm (six adenomas, three cysts, and one hyperplasia) were evaluated retrospectively. Urinary metanephrines were evaluated by HPLC.

Results: In PHEO group urinary metanephrines were as follows: 3 (25%) had borderline elevations, 9 (75%) had normal values, however 1 (10%) had borderline elevation, 1 (10%) had sixfold elevations, and 8 (80%) had normal values in non-PHEO group. The difference was evaluated as statistically insignificant (P=0.19). Normetanephrine values were as follows: borderline elevation in 5 (41.7%), twofold elevation in 1 (8.3%), sixfold elevation in 1 (8.3%), and normal values in 5 (41.7%) patients in PHEO group; borderline elevations in 2 (20%), twofold elevation in 1 (10%), normal values in 7 (70%) patients in non-PHEO group. This was also statistically insignificant (P=0.39). There were also no significant differences in urinary adrenaline and noradrenaline levels between groups.

Conclusion: Patients with borderline-elevated urinary metanephrine levels can also have PHEO. In patients with adrenal incidentalomas who are candidate for surgery and have borderline elevated metanephrines should be evaluated carefully. In this group of patients, we advocate either routine preoperative preparation as patients possessing PHEO or further diagnostic tests in order to prevent the serious complications.