Large degenerated adrenal adenomas: Radiologic-pathologic correlation

PURPOSE: To correlate the radiologic and pathologic findings and differenti al diagnosis of large, degenerated adrenal adenomas. MATERIALS AND METHODS authors reviewed the radiologic and pathologic charac teristics of 30 large adenomas with cystic regions or areas of heterogeneit y that were either intrinsic or demonstrated at contrast material-enhanced computed tomography(CT) or magnetic resonance(NIR) imaging. Images of 24 ad renocortical carcinomas were also reviewed to determine whether differentia ting characteristics . RESULTS: Most of the adrenocortical adenomas were in asymptomatic women. Te n adenomas contained calcification. Pathologic examination revealed good co rrelation between heterogeneity and liquefied regions. Histologic examinati on confirmed regions of adenomatous tissue with areas of hemorrhage, amorph ous degenerated material calcification, and fibrosis. Some tumors contained myelolipomatous foci. Although some clinical and imaging findings differed between the groups, no features could be found that enabled the radiologic differentiation of adenomas from carcinomas. CONCLUSION: A subgroup of adrenal adenomas are larger, more heterogeneous, and more frequently calcified than those with the usual imaging findings. C entral necrosis, hemorrhage, or both are responsible for many of the imagin g features. Differentiation of these lesions from other large adrenal masse s, including adrenal carcinoma, cannot be made by means of imaging alone; r esection is required for the definitive diagnosis.