title: Enlarged clitoris in wild polar bears (Ursus maritimus) can be misdiagnosed as pseudohermaphroditism.
abstract: A 23-year-old female polar bear (Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported 'pseudohermaphroditic' polar bears from Svalbard. It has been suggested that an enzyme defect (21-hydroxylase deficiency), androgen producing tumour or high exposure to organochlorines during the foetal stage or early development could be the reason for the supposed pseudohermaphroditism observed for Svalbard bears. Except for the enlarged clitoris, all dimensions of the external and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. A histological examination of the clitoral enlargement in the present East Greenland specimen allows a first-time histological evaluation of the earlier macroscopic field diagnosis from Svalbard. This examination revealed intense chronic ulcerative and perivascular clitoriditis similar to "acral lick dermatitis" frequently seen in domestic dogs (i.e., we did not find any signs of pseudohermaphroditic hyperplasia of clitoral tissue due to androgenic or antiestrogenic endocrine disruption). The levels of organohalogens and TEQ values were lower than concentration thresholds of toxicological risk. It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphroditism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East Greenland polar bear. Furthermore, caution should be exercised in suggesting linkages of such inflammatory abnormalities with correlations to anthropogenic pollutant exposures.
authors.affiliation: Department of Arctic Environment, National Environmental Research Institute, Frederiksborgvej 399, Box 358, DK-4000 Roskilde, Denmark. csh@dmu.dk
authors.forename: C
authors.initials: C
authors.lastname: Sonne
authors.forename: P S
authors.initials: PS
authors.lastname: Leifsson
authors.forename: R
authors.initials: R
authors.lastname: Dietz
authors.forename: E W
authors.initials: EW
authors.lastname: Born
authors.forename: R J
authors.initials: RJ
authors.lastname: Letcher
authors.forename: M
authors.initials: M
authors.lastname: Kirkegaard
authors.forename: D C G
authors.initials: DC
authors.lastname: Muir
authors.forename: L W
authors.initials: LW
authors.lastname: Andersen
authors.forename: F F
authors.initials: FF
authors.lastname: Riget
authors.forename: L
authors.initials: L
authors.lastname: Hyldstrup
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D015519:Bone Density; D002987:Clitoris / Q000473:pathology*; D003937:Diagnosis, Differential; D004147:Dioxins / Q000032:analysis / Q000378:metabolism; D012734:Disorders of Sex Development / Q000175:diagnosis / Q000662:veterinary*; D004784:Environmental Monitoring / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D005260:Female; D005831:Genital Diseases, Female / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D006116:Greenland; D006846:Hydrocarbons, Halogenated / Q000032:analysis / Q000378:metabolism; D007249:Inflammation / Q000473:pathology; D019055:No-Observed-Adverse-Effect Level; D009929:Organ Size; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D012886:Skull / Q000737:chemistry / Q000378:metabolism; D001503:Ursidae / Q000378:metabolism
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D006846:Hydrocarbons, Halogenated; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls