Fig. 23.16 Cushing's syndrome: hypertrophy of the adrenal glands demonstrated by CT. Most cases of Cushing's syndrome are caused by increased ACTH production by the pituitary gland. The remainder are due either to an ectopic ACTH-producing tumour or to a primary adrenal tumour (adenoma or carcinoma). Increasing ACTH levels result in adrenal hyperplasia with accompanying hypertrophy. Small changes in size cannot be detected by CT and the adrenals may therefore appear normal. More marked hypertrophy can be shown as thickening of the limbs of the gland with convexity of the margins. The normal configuration is, however, retained.
