Abstract / Summary
Retroperitoneal teratomas are uncommon pediatric germ cell tumors and are exceptional during the neonatal period.Their diagnosis and treatment are challenging because they may compress major abdominal vessels and involve adjacent organs.We report the case of a two-day-old male neonate who presented with progressive abdominal distension and a palpable abdominal mass.Ultrasonography and computed tomography demonstrated a 9 × 9 cm heterogeneous retroperitoneal lesion with solid, cystic, and calcified components, associated with displacement of bowel loops, compression of major vessels, and apparent pancreatic involvement.Exploratory laparotomy with tumor resection was performed.Intraoperatively, the lesion showed macroscopic structures resembling a hand and a foot, raising the differential diagnosis of fetus in fetu.The pancreatic tail was considered involved intraoperatively and was resected, while the pancreatic head and body were preserved.Histopathological examination confirmed a grade 3 extragonadal immature teratoma with no vertebral axis.The pathology report also described partial pancreatic tail involvement; however, the available pathology documentation did not further characterize the pancreatictumor interface or the pancreatic resection margin.The postoperative hospital course was favorable, although prolonged neonatal intensive care was required.This case highlights the importance of preoperative imaging, careful retroperitoneal dissection, vascular control, patient-specific clarification of distorted anatomy, and histopathological confirmation when evaluating complex neonatal abdominal masses.