Is computed tomography guided biopsy still necessary for the diagnosis of adrenal masses in patients with resectable non-small-cell lung cancer?

Objectives: This study was undertaken: (1) to evaluate the usefulness of un enhanced computed tomography (CT), magnetic resonance imaging (MRI) and CT guided biopsy for the characterization of adrenal masses in patients with o perable non-small-cell lung cancer (NSCLC) and (2) to evaluate the situatio ns in which CT guided biopsy is absolutely necessary before potentially cur ative resection of NSCLC. Methods: Consecutive patients with operable NSCLC underwent unenhanced adrenal CT with density measurements of any adrenal m ass over 1 cm in diameter. An adrenal mass was considered as an adenoma whe n its density was below 10 Hounsfield Units and a metastasis when its densi ty exceeded 10 Hounsfield Units. Then patients underwent MRI, the signal on the T2 weighted images from the enlarged gland was classified adenoma or m etastasis in comparison with that from the liver parenchyma. CT guided biop sy was performed after a pheochromocitoma was eliminated. Unenhanced CT att enuation values and signal intensity values on MRI were correlated with his topathologic results. Results: Of the 443 patients, 32 had an adrenal mass consisting of adrenal metastases in 18 cases and adenomas in 14 cases. On C T, 3/14 (21%) of the adenomas were misdiagnosed as metastases (their densit ies exceeded 10 Hounsfield Units) and 2/18 (11%) Of the metastases were mis diagnosed as adenomas (their densities were below 10 Hounsfield Units). On MRI, none of the metastases were misdiagnosed as an adenoma (100% sensitivi ty) but 7/14 (50%) of the adenomas were misdiagnosed as metastases (signal superior to that of liver). Overall, a diagnostic certainty of metastasis c ould not be obtained in 25/32 patients (78%). CT guided biopsy with 100% se nsitivity and specificity corrected all the inaccurate results of CT and MR I without any morbidity. Conclusion: Despite extensive morphological evalua tion with unenhanced CT and conventional MRI, CT guided biopsy is necessary for most patients referred to surgery for an operable NSCLC and an adrenal mass. (C) 1999 Elsevier Science B.V. All rights reserved.