Published online Dec 26, 2021. doi: 10.12998/wjcc.v9.i36.11482
Peer-review started: September 2, 2021
First decision: September 29, 2021
Revised: October 11, 2021
Accepted: November 18, 2021
Article in press: November 18, 2021
Published online: December 26, 2021
Processing time: 112 Days and 5.4 Hours
Fetus-in-fetu (FIF) is an extremely rare congenital abnormal mass, in which a normal fetus’s vertebral axis frequently connected with malformed fetus around this axis. Here, we report the case of a male infant aged 26 d presenting with retroperitoneal parasitic fetus.
In a prenatal examination, we first detected an abdominal mass measuring 7.8 cm × 5.1 cm × 6.8 cm in a mother’s abdomen at 25 gestational weeks and teratoma was suspected. After the fetal was born, we did a magnetic resonance imaging (MRI) and ultrasonography on him and saw a distinctive limb with five-toes. According to the result of MRI, ultrasonography and postoperative pathology, he finally was diagnosed with FIF.
A laparotomy was performed at 26 d of age with excision of the retroperitoneal cystic tumor, which measured about 10 cm in diameter. According to the result of imaging and histological test, FIF was confirmed.
Core Tip: Fetus-in-fetu (FIF) is a rare pediatric disease that many clinicians have not faced. In this case, we summarize the features and antidiastole of FIF with radiology, especially magnetic resonance imaging and ultrasound, cross-sectional ultrasonic imaging helps in differentiating it from teratoma. Clinicians’ preliminary understanding of FIF facilitates to achieve early discovery, early diagnosis, early treatment.