In general the adrenals have a ‘wishbone‘, or upside down ‘y’ shape, but they are not usually symmetrical. Although they are naturally asymmetric structures, part of their shape discrepancy relates to the variability in their surroundings. Since they are in different relative positions they have different surroundings.When there is a paucity of fat or the surrounding structures push on them, they tend to distort. The right adrenal gets pushed against the liver, and elongates, while the left becomes irregular and “knobbly”. Thus in general, the right is long and thin and the left short and stout. When there is a large amount of retroperitoneal fat they tend to look more alike in cross section.
In general the adrenal glands are triangular in shape and are reminiscent of the shape of the “wishbone” or the breast bone of the chicken.Courtesy of: Ashley Davidoff, M.D.The right adrenal gland, in this case, looks exactly like the inserted drawing of the “wishbone”. This represents the typical appearance of the glands – the right long and thin, and the left short and stout. The bright red overlays represent some of the branches of the adrenal arteries.Courtesy of: Ashley Davidoff, M.D.The adrenal glands should be well defined, and be free of nodularity, such as seen in this normal case. The distinction between “knobbly normal”, and “knobbly hyperplasia” (disease) as stated previously, is a difficult but very important distinction to make.Courtesy of: Ashley Davidoff, M.D.This case shows bilateral nodularity caused by bilateral adrenal adenomas. The abnormal areas are overlayed in green and the normal adrenal outlined in yellow.Images courtesy of: Ashley Davidoff, M.D.
