An adrenal pseudocyst is a rare, benign mass of the adrenal gland. A pseudocyst is a cystic mass enclosed by a fibrous capsule and filled with blood and fibrinous material. In contrast to a typical cyst, a pseudocyst does not have an epithelial lining. Most adrenal pseudocysts are unilateral. Adrenal cysts are more common in women and typically are found in patients between the ages of 30 and 60. Adrenal pseudocysts are mostly benign, with an approximately 7% risk of malignancy or premalignancy. Larger adrenal pseudocysts (> 6 cm) portend a higher malignancy risk.

Adrenal pseudocysts usually develop after an adrenal injury, such as hemorrhage caused by trauma or infection. Adrenal pseudocysts may be an incidental finding on imaging, but they can present with abdominal pain or obstruction of the gastrointestinal tract. Rarely, adrenal pseudocysts can rupture and cause hemorrhage or shock.

If symptomatic, adrenal pseudocysts can be surgically excised, typically with an excellent prognosis.