Small prebiochemical pheochromocytoma

Unenhanced (A) and enhanced (B) axial CT images from a 49-year-old male who presented with right-sided abdominal discomfort. A 1.6 cm left adrenal mass was incidentally discovered (arrows). On the unenhanced image, the CT attenuation was 40 HU and diagnostic of a lipid-poor mass. With contrast administration, the adrenal nodule was very vascular (B) and had slow contrast washout (<50% at 10 minutes). The patient was normotensive and had no signs or symptoms of adrenal-related disease. The plasma fractionated metanephrines and 24-hour urine fractionated metanephrines and catecholamines were normal. However, in view of the suspicious imaging phenotype and the patient's young age, surgical resection after alpha-adrenergic blockade was advised. On pathology, it proved to be a 2.1 × 1.7 × 1.3 cm pheochromocytoma.