Laparoscopic resection of giant retroperitoneal mature cystic teratoma with diaphragm invasion in a 3-month-old girl

Primary retroperitoneal teratomas are rare, representing only 1%–11% of primary retroperitoneal neoplasms. They typically present as an asymptomatic abdominal mass but can grow to enormous size. The majority of these are benign mature and immature teratomas. We found a large mass in the left abdomen of the child. According to examinations (CT, Ultrasound, Tumor markers, etc.), it was considered to be benign, which was treated by laparoscopic surgery. However, CT revealed that part of the diaphragm was invaded, increasing the difficulty of our operation and intraoperatively confirmed the invasion of the left diaphragm. A frozen section and final histopathologic examination also revealed mature cystic teratoma. This case study highlights the importance of pre-operative imaging and tumor markers. Under the premise of ensuring the safety of the child, laparoscopic procedures have resulted in decreased tissue trauma and accelerated postoperative recovery.