A giant primary retroperitoneal mature cystic teratoma in right adrenal region in a 39-year-old female.

We report an unusual case of a giant primary retroperitoneal mature cystic teratoma in right adrenal region in a 39-year-old Chinese female. The patient has complained of dizziness and a high blood pressure approximately 170/110 mmHg for half one year. A plain helical and enhanced CT scan showed a huge tumor with a mixing density in recessus hepatorenalis. This tumor had calcification and fat, as well as a mild enhancement in part of the tumor. The patient was successfully treated with a right surgical resection of the mass. Although the primary retroperitoneal mature cystic teratomas in right adrenal regions are extremely rare, we should pay attention to it and close follow up is indispensable on account of the incidence of malignant transformation is approximately 3-6%.