A step by step approach in differential diagnosing of adrenal
incidentaloma (epinephroma), (with comments on the new Clinical Practice
Guidelines of the European Society of Endocrinology)
Objectives. To present a step by step approach for the diagnosis of
adrenal incidentaloma (AI).
Method. An extensive review of the literature was conducted, searching
the Pub-Med and Google Scholar using the Mesh terms; Adrenal;
Incidentaloma; Adrenal tumours; Radiology; Diagnosis. We also did a
cross-referencing search of the literature. Comments on the new European
guidelines are presented.
Results. The majority of the tumours are non-functioning benign
adenomas. The most important radiological characteristic of an adrenal
incidentaloma is the radiation attenuation coefficient. Wash out
percentage and the imaging characteristics of the tumour may help in
diagnosis.
Conclusion. Density less than 10 HU is in most cases characteristic of a
lipid rich benign adenoma. More than 10 HU or/and history of malignancy
raise the possibility for cancer. 1 mg dexamethasone test and plasma
metanephrines should be done in all patients. If there is history of
hypokalemia and/or resistant hypertension we test the plasma aldosterone
to plasma renin ratio (ARR). Newer studies have shown that tumours even
nonfunctioning and less than 4 cm may increase the metabolic risks so we
may consider surgery at an earlier stage
