Adrenal Hyperplasia

adrenal gland appearance has some variability but are classically described as inverted Y, V or T-shaped.
width of normal adrenal gland limb is 4-9 mm and weight is around 5 grams
width over 10 mm is consistent with hyperplasia
adrenal hyperplasia can be unilateral or bilateral
in hyperplasia adrenal shape is maintained
Cushing’s syndrome is caused in 80% of cases by bilateral adrenal hyperplasia
adrenal hyperplasia can be a result of primary hyperaldosteronism. In these cases the adrenal glands may also appear nodular

enlarged limbs of one or both adrenal glands over 10mm
no discrete mass or nodule seen except in cases of Cushings due to macronodular hyperplasia

MR defines the glands within retroperitoneal fat but adds no new information to the CT Scan in these cases

most cases are picked up as incidental findings on a CT scans
30% of cases of primary hyperaldosteronism are due to bilateral adrenal hyperplasia (70% due to adenoma)
80% of cases of Cushing’s disease are caused by bilateral adrenal hyperplasia. Up to one-third of these cases show a normal adrenal gland based solely on CT criteria

in cases without clinical symptoms careful follow up is indicated
in cases with symptoms surgery may be indicated depending on wheteher the process is unilateral or bilateral

Spectrum of CT Findings in nonmalignant disease of the adrenal gland
Kawashima A, Sandler CM, Fishman EK et al
RadioGraphics 1998;18:393
Primary aldosteronism:an endocrine perspective
BlevinsLS, Wand GS
Radiology 1992;184:599
Cleveland clinic experience with adrenal Cushing’s syndrome
Daitch JA, GoldfarbDA, NovickAC
J Urol 1997;158:2051