Endocrine Abstracts

Introduction: Adrenal incidentaloma is an adrenal mass found on imaging studies done for other reason than suspected adrenal disease. The majority of them are non-functioning adenomas, however pheochromocytomas could be also observed. Currently, in diagnosis of incidentalomas, the assessment of hormones of adrenal cortex and medulla is performed. The aim of the study was to assess the incidence of pheochromocytoma in patients with incidentaloma.

Methods: Medical records of 380 patients with incidentaloma hospitalized during 14 months in our clinic were retrospectively reviewed. Diagnostic imaging pictures, the incidence of hypertension, urine metoxycatecholamines secretion (normetanefrine or metanefrine), as well as hormonal assessment of adrenal cortex were analyzed.

Results: Seventy eight percent of patients were hypertensive. Most of lesions have benign features on imaging study. There were only nine histopatologically confirmed pheochromocytomas, which comprises 2.37% of all cases. In those nine patients, only one person have adenoma-like characteristic on imaging study. Accurate levels of metoxycatecholamines were known in 304 patients of total 380. Forty-three patients (14.1%) have elevated level of metoxycatecholamines. In this group of 43 patients 7 (16.3%) patients have histopatologically confirmed pheochromocytoma. Thirty five patients do not have pheochromocytoma in spite of elevated metoxycatecholamines. Moreover, two patients with pheochromocytoma have unelevated metoxycatecholamines secretion with benign features on imaging study in one of those patients.

Conclusion: 1 The assessment of urine metoxycatecholamines secretion seems to have limited usefulness in diagnosis of pheochromocytoma, mainly because of low incidence of elevated level of metoxycatecholamines and possibility of false positive results.

2 Moreover, normal level of urine metoxycatecholamines secretion were also oberved in some patients with pheochromocytoma.

3 In diagnosis of pheochromocytoma, clinical symptoms and radiological imaging picture should play the most important role.

4 Assessment of urine metoxycatecholamines secretion should be performed in justified cases.