Adrenal masses in oncologic patients: functional and morphologic evaluation.

The role of adrenocortical scintigraphy in the evaluation of unilateral adrenal masses detected with computed tomography (CT) in 28 oncologic patients with normal adrenal function was studied prospectively with the use of NP-59 (iodine-131-6-iodomethyl-19-norcholesterol). The diagnosis was proved by means of percutaneous fine-needle aspiration cytologic examination in 20 patients, surgical biopsy in one, and clinical and CT follow-up in seven. In 14 of the 28 patients, there was increased uptake of the NP-59 on the side of the adrenal mass detected at CT (concordant uptake). Thirteen of the 14 masses with concordant uptake were greater than 2 cm in diameter, and one was 1.5 cm; all were found to be adenomas. In 11 of 28 patients there was decreased uptake on the side of the mass detected at CT (discordant uptake). None of these 11 masses were adenomas; nine were metastases and two were adrenal cysts. Uptake was indeterminate (symmetric) in three patients, two of whom had adrenal adenomas and one an adrenal metastasis; each mass with indeterminate uptake was less than 2 cm in diameter.