28-YR-OLD woman presented with a 3-month history of right hip pain without accompanying systemic symptoms or a preceding history of trauma. The patient had magnetic resonance imaging and computerized tomography (CT) of the abdomen and pelvis, which showed a very large cystic mass in the right retroperitoneum that was displacing the right kidney, ascending colon, pancreas, and duodenum into the left side of the abdomen (Figs. 1 and 2). Subsequent evaluation at our institution was performed. On physical examination, the patient was normotensive, and the only remarkable finding was right upper quadrant fullness. A complete adrenal assessment revealed no evidence of hor- mone overproduction. Initial aspiration of the cyst yielded 1500 ml yellow fluid with no evidence of malignant cells. Afteraspiration,CTshowedalargeresidualcysticmasswith the limbs of the right adrenal gland on its surface (Fig. 3). Definitive treatment was undertaken via open adrenalec- tomy. Pathologically, the specimen contained hemorrhagic fluid and was surrounded by a pseudocapsule with no clear lining epithelium or endothelium, confirming the diagnosis of an adrenal pseudocyst.