Abstract
Primary retroperitoneal teratoma is a relatively rare disease that occurs most often in children and is very rare in adults. An adult case with a diagnosis of mature cystic teratoma treated by surgical resection is presented. A 78-year-old woman visited our hospital because of back pain, and a diagnosis of a retroperitoneal tumor was made on CT scan. The tumor was about 8 cm×5 cm and was in front of the left ovarian artery. As preoperative diagnose, mucinous tumor, teratoma, and so on were suspected, and tumor resection was performed. The resected specimen was a cystic tumor with a smooth surface, filled with a brownish-red viscous liquid. Histopathologically, the tumor was a cystic tumor with a sebaceous gland, and the diagnosis was mature cystic teratoma without malignant findings. The patient's postoperative course was uneventful, and the patient was discharged from the hospital on the 8th postoperative day. Primary retroperitoneal mature cystic teratoma is a very rare disease in adults. A case with malignant transformation has a poor prognosis, but in a case found before malignant transformation, resection provides a good prognosis. Surgical resection should be performed for retroperitoneal teratoma in adults.
