Differentiation of malignant from benign adrenal masses: predictive indices on computed tomography.

CT findings in 43 adrenal masses were analyzed to see which features correlated most significantly with malignancy. Size, contrast enhancement, and consistency emerged as important discriminators of malignant from benign adrenal masses. These three factors were further analyzed by logistic regression technique to examine the joint influence of computed tomographic (CT) features in prediction of malignancy. As a result of logistic regression analysis, a table of estimated probability of malignancy as a function of tumor size alone and another table of estimated probability as a joint function of size and contrast enhancement were developed. Given a similar patient sample and by using the data given, it would be possible to predict chances of malignancy in an adrenal mass if its CT features are known; for example, a 5-cm adrenal mass without enhancement has a 0.31 probability of malignancy; with enhancement, a 0.68 probability.