Retroperitoneal cystic lymphangyoma is a benign lesion, extremely rare in adults. In most cases is asymptomatic. The objective of this report is to present the case of an 82 year old woman who presented abdominal pain, food intolerance and a palpable abdominal mass located toward the upper right quadrant. The abdominal CT scan showed a cystic lesion below the liver which extended to the retroperitoneum. The patient underwent laparotomy achieving complete resection of the lesion and she was discharged soon after. After six months of follow up, she has not presented recurrence. The presentation of this lesion is very rare, generally as a consequence of congenital malformations of the lymphatic vessels. These lesions must be considered as part of the differential diagnosis of the cystic type tumors. The ultrasound and abdominal CT scan are useful for diagnosis. Surgical resection is the only therapeutic option.