Imaging features of uncommon adrenal masses with histopathologic correlation

Uncommon adrenal masses include cystic lesions (hydatid cyst, endothelial c yst), solid lesions (hemangioma, ganglioneuroma, angiosarcoma, primary mali gnant melanoma), and solid fatty lesions (myelolipoma, collision tumor). Mo st of these lesions do not have specific imaging features. The liquid conte nt of adrenal cysts is clearly demonstrated on ultrasonographic scans, comp uted tomographic scans, and magnetic resonance Nevertheless, the histologic type cannot be predicted except at some stages of hydatid disease in which pathognomonic features are present. The most typical imaging features of h emangioma are phleboliths and enhancement of peripheral vascular lakes. Gan glioneuroma has non-specific specific radiologic features, but this diagnos is should be considered in cases with early enhancement of fine septa and p rogressive filling. The radiologic features of angiosarcoma and primary mal ignant melanoma are nonspecific, A macroscopic lipid content within an adre nal mass is theoretically characteristic of myelolipoma. This diagnosis sho uld be made with caution, especially when the lipid content is not predomin ant, because of the possible association with an adenoma.