Retroperitoneal teratoma (RPT) is an exceedingly rare neoplasm in infancy. Due to their rarity, we are reporting a case of retroperitoneal cystic teratoma in four months old infant involving pelvic mesocolon. The tumor was completely excised, and the patient was successfully discharged. Histopathological examination confirmed the diagnosis of mature cystic teratoma.
Keywords: Alpha-fetoprotein, germ cell tumors, retroperitoneal teratoma.