Role of ct in investigation of an incidental adrenal lesion later confirmed to be a phaeochromocytoma

Adrenal “incidentalomas” are defined as adrenal masses detected during USG, CT or MRI examination in patients for whom imaging studies are being performed for an unrelated indication. Approximately 3 to 4 percent of CT and MRI studies of the abdomen reveal an adrenal incidentaloma. The overwhelming majority of these lesions comprise benign nonfunctioning adenomas in the asymptomatic patient with no history of malignancy. However, this does not hold true for oncologic patients, as the adrenal glands are a common site for metastatic disease. Adrenal metastasis may be found in 25% of patients with known primary. Adrenal incidentalomas (5cm or larger) are detected in 1-10% of abdominal CT and MRI scans, 2-9% of autopsies, 4% of chest CT scans. Adrenal incidentaloma is higher in whites than blacks and in obese, diabetic, hypertensive patients. 3-7% of adrenal incidentalomas are pheochromocytomas. Of additional concern are lesions that are hormonally active and the rare primary adrenocortical carcinomas. 35% of adrenal tumours are non-functioning and may not need treatment. For this reason, differentiating the lesions that warrant treatment from those benign, inconsequential masses that should be left alone is essential.