[CT guided adrenal biopsies: remaining indications?].

The need for adrenal gland biopsy has much decreased since CT and MR criteria have been introduced for further characterization of adrenal lesions. Several diagnostic criteria have been described for characterization of benign versus malignant adrenal lesions based on density measurements and contrast wash-out. Adrenal biopsy may be indicated for lesions that remain indeterminate in nature after CT and MRI. Such lesions include those with a percentage of wash-out near the 50% threshold or lesions that have increased in size at follow-up imaging in spite of their benign appearance based on density measurement at prior CT evaluation. The location of the adrenal glands has an impact on the technical difficulties during biopsy and the types of complications. Ipsilateral lateral decubitus seems the more logical approach and can be used for right or left adrenal lesions; this approach is generally well tolerated by patients. Biochemical evaluation should be performed prior to biopsy in order to exclude pheochromocytoma. The overall accuracy of adrenal biopsy, considering both positive predictive value and negative predictive value, compared to the gold standard is between 80 and 95% with a complication rate of about 10%.