Relationship between Clear Cell/Compact Cell Ratio and Computed Tomographic Attenuation Number in Adrenocortical Adenoma

Clear cell/compact cell ratio in histologic sections from 21 resected adrenocortical adenomas was assessed. Seven patients had Cushing's syndrome another 7 had primary aldosteronism caused by adrenal adenomas and 7 had non-hyperfunctioning adenomas. The results were correlated with the corresponding unenhanced CT attenuation numbers. There was a negative correlation between clear cell/compact cell ratios and unenhanced CT attenuation numbers. However, CT attenuation numbers did not show significant differences between cortisol-producing, aldosterone-producing and nonfunctioning adenomas. These facts suggest that clear cell/compact cell ratio in adrenocortical adenomas accounts for their attenuation number on unenhanced CT scans. However, it is difficult with the use of unenhanced CT attenuation numbers to differentiate cortisol-producing adenomas from aldosterone-producing and nonhyperfunctioning adenomas.