title: Fetus in fetu in a harbor seal (Phoca vitulina richardi): histopathologic, genetic, and toxicologic analysis.
abstract: A young harbor seal (Phoca vitulina richardi), stranded on the coast of California, was found to have a 20-cm-diameter cranial cervical mass. Surgical excision revealed the subcutaneous mass to be covered in haired skin with multiple glabrous areas and structures resembling a jaw with tooth buds, eyelids, and a tail. The mass deformed the host pup's skull. Histologic examination revealed a complete vertebra in the tail, teeth in the jaw, and areas resembling tongue and larynx. Class 1 MHC sequences amplified by polymerase chain reaction from the mass and the host twin were identical. The mass was diagnosed as a fetus in fetu, a rare congenital anomaly in which 1 conjoined twin is completely enclosed in the body of the other twin. The host pup died, and no additional defects were found; however, blubber levels of persistent organic pollutants were high. The cause of the congenital anomaly in this pup is uncertain.
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, One Shields Avenue, University of California at Davis, Davis, CA 95616 (USA).
authors.forename: E L
authors.initials: EL
authors.lastname: Buckles
authors.forename: F M D
authors.initials: FM
authors.lastname: Gulland
authors.forename: B M
authors.initials: BM
authors.lastname: Aldridge
authors.forename: T S
authors.initials: TS
authors.lastname: Gelatt
authors.forename: P S
authors.initials: PS
authors.lastname: Ross
authors.forename: M
authors.initials: M
authors.lastname: Haulena
authors.forename: L J
authors.initials: LJ
authors.lastname: Lowenstine
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004785:Environmental Pollutants / Q000378:metabolism; D017809:Fatal Outcome; D005260:Female; D005333:Fetus / Q000002:abnormalities; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006651:Histocytochemistry / Q000662:veterinary; D046049:Phoca / Q000002:abnormalities* / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000662:veterinary; D014428:Twins, Conjoined / Q000473:pathology*; D014430:Twins, Monozygotic
chemical_list: D004785:Environmental Pollutants; D015395:Histocompatibility Antigens Class I; D004247:DNA