A 32-year-old woman was admitted because of a large abdominal mass in the right upper quadrant. Laboratory findings including hormonal studies were within normal ranges. CT scan and various X-ray examinations revealed a large adrenal cyst on the right side. On May 2, 1984, an adrenal cyst was removed through the right flank incision. Histological study showed that the wall of the cyst consisted of fibrous tissue with endothelial linings and dilated lymphatic vessels. Thus it was classified as a lymphangiomatous adrenal cyst.