Shih H.-H.Teng R.-J.Tsou Yau K.-I.HO-HSIUNG LINFON-JOU HSIEHChen C.-C.2021-03-032021-03-0319970960-7692https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030787166&doi=10.1046%2fj.1469-0705.1997.10030209.x&partnerID=40&md5=57265254811162487d3c77ff673ad05ehttps://scholars.lib.ntu.edu.tw/handle/123456789/550261Teratoma of the intra-abdominal testis is a rare finding in infants. We describe the case of a full-term newborn treated for a calcified abdominal mass which was observed unexpectedly on prenatal sonography. An undescended right testis was also noted. During laparotomy, a twisted retroperitoneal tumor was found just above the right deep inguinal ring. Histological analysis revealed a mature teratoma of the intra-abdominal right testis. The tumor was removed and there was no recurrence at follow-up 1 year later. A teratoma should be considered in cases of fetal abdominal mass, especially when the testes cannot be detected in the scrotum by the 8th month. Prenatal sonographic diagnosis might be possible.[SDGs]SDG3abdominal tumor; adult; article; case report; cryptorchism; echography; female; fetus; fetus echography; human; laparotomy; male; newborn; prenatal screening; priority journal; teratoma; testis teratoma; Adult; Cryptorchidism; Diagnosis, Differential; Disease-Free Survival; Female; Fetal Diseases; Humans; Infant, Newborn; Laparotomy; Male; Pregnancy; Teratoma; Testicular Neoplasms; Ultrasonography, Prenataljournal article10.1046/j.1469-0705.1997.10030209.x93395292-s2.0-0030787166