Two Cases of Primary Retroperitoneal Mature Cystic Teratoma in Adults

Abstract

Adult-onset primary retroperitoneal mature cystic teratoma is a rare disease. We report two cases treated by surgical resection. Case 1: A 49-year old woman received a diagnosis of a 7×6 cm tumor which size during pregnancy at age 30. Because priority was given to the birth, the tumor was scheduled for follow-up. However, she did not visit our hospital after delivery. When she was 49 years old she complained of urinary retention and was referred to our hospital. The same diagnosis was given again but the tumor had increased to 17 cm in diameter in the pelvis and the tumor was resected with coccygeal bone. Case 2: In a 23-year old woman a retroperitoneal tumor was diagnosed during cesarean section. She was then given a diagnosis of a lobular tumor of 9×7 cm anterior to the sacrum and the tumor was resected with coccygeal bone. The pathological diagnoses showed that both cases were benign mature cystic teratomas. Primary retroperitoneal mature cystic teratoma in adults is very rare. Some reports says that this tumor has the potential of malignant transformation and has a poor prognosis. Thus we need immediate operation before malignant transformation, because we can achieve a good prognosis only by surgical resection.