We present the case of a 36 year old female patient with a 3 month history of severe lower back pain without improvement after physiotherapy and analgesic drug therapy. X-rays of the spine were normal except for a calcified paravertebral lesion on the right side. A cystic tumor projecting on the posterior area of the right liver lobe was seen using ultrasound. MRI-scan showed an extrahepatic localization of the tumor. Intraoperatively, the tumor was located in the right adrenal gland which was then removed. Histopathology revealed an adrenal pseudocyst, and the pain was gone immediately after surgery.