title: Fetus in fetu in an adult: diagnosis by computed tomography imaging.
abstract: The term "fetus-in-fetu" refers to a monozygotic, diamniotic twin that is incorporated into the body of another sibling early in embryonic development. A fetus in fetu is a differentiated mass that, in contrast to a teratoma, has a discrete spinal column and well developed internal organs. Most cases of fetus-in-fetu are discovered as a retroperitoneal mass in the first year of life, and the condition is unusual in adulthood. We describe a case of fetus-in-fetu incidentally discovered in a 39-year-old man who complained of mild epigastralgia. Abdominal ultrasound revealed a mass at the right upper quadrant of the abdomen. Fetus-in-fetu was diagnosed by computed tomography as an incidental finding, which was not clearly related to his abdominal discomfort. The fetus-in-fetu was treated conservatively. His radiologic as well as clinical condition remained unchanged during 4 years of follow-up.
authors.affiliation: Departments of Medical Imaging, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Cheng-Chun
authors.initials: CC
authors.lastname: Lee
authors.forename: Kao-Lang
authors.initials: KL
authors.lastname: Liu
authors.forename: Yuk-Ming
authors.initials: YM
authors.lastname: Tsang
authors.forename: Shy-Jye
authors.initials: SJ
authors.lastname: Chen
authors.forename: Ho-Man
authors.initials: HM
authors.lastname: Liu
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005333:Fetus / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D014057:Tomography, X-Ray Computed; D014430:Twins, Monozygotic