title: Fetus-in-fetu in the cranium of a 4-month-old boy: histopathology and short tandem repeat polymorphism-based genotyping. Case report.
abstract: Fetus-in-fetu is a very rare condition in which one fetus is contained within another. About 100 cases have been reported, and in most of these the fetus was located in the retroperitoneum. The authors describe an extremely rare case of an intracranial fetus-in-fetu in an extraaxial location. This is the eighth intracranial fetus-in-fetu to be reported, the first intracranial extraaxial case, and involves the oldest documented patient with this condition. Histopathological analysis of the mass revealed a degenerated amnionic membranelike tissue, well-differentiated extremities (including fingerlike structures), skin, matured lungs, well-formed intestines, cerebellar and cerebral tissue, and a notochord with ganglion cells. DNA analysis using short tandem repeat polymorphisms confirmed that the fetus-in-fetu mass and the host infant had heterozygous alleles and were of identical sex and genotype.
authors.affiliation: Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Sung-Hye
authors.initials: SH
authors.lastname: Park
authors.forename: Sung-Sup
authors.initials: SS
authors.lastname: Park
authors.forename: Kyu-Chang
authors.initials: KC
authors.lastname: Wang
authors.forename: Byung-Kyu
authors.initials: BK
authors.lastname: Cho
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Ra
authors.forename: Chae-Yong
authors.initials: CY
authors.lastname: Kim
authors.forename: Seung-Ki
authors.initials: SK
authors.lastname: Kim
mesh_terms: D001921:Brain / Q000002:abnormalities* / Q000601:surgery; D005333:Fetus / Q000002:abnormalities*; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics; D014430:Twins, Monozygotic