title: The Significance of the Discordant Occurrence of Lens Tumors in Humans versus Other Species.
abstract: OBJECTIVE
  The purpose of this study was to determine in which species and under what conditions lens tumors occur.
  
  
  METHODS
  A review of databases of available human and veterinary ocular pathologic material and the previously reported literature.
  
  
  METHODS
  Approximately 18 000 patients who had ocular surgical specimens submitted and studied at the University of Wisconsin School of Medicine and Public Health between 1920 and 2014 and 45 000 ocular veterinary cases from the Comparative Ocular Pathology Laboratory of Wisconsin between 1983 and 2014.
  
  
  METHODS
  Material in 2 major archived collections at the University of Wisconsin medical and veterinary schools were studied for occurrence of lens tumors. Tumor was defined as a new growth of tissue characterized by progressive, uncontrolled proliferation of cells. In addition, cases presented at 3 major eye pathologic societies (Verhoeff-Zimmerman Ophthalmic Pathology Society, Eastern Ophthalmic Pathology Society, and The Armed Forces Institute of Pathology Ophthalmic Alumni Society) from 1975 through 2014 were reviewed. Finally, a careful search of the literature was carried out. Approval from the institutional review board to carry out this study was obtained.
  
  
  METHODS
  The presence of tumors of the lens.
  
  
  RESULTS
  The database search and literature review failed to find an example of a lens tumor in humans. In contrast, examples of naturally occurring lens tumors were found in cats, dogs, rabbits, and birds. In the veterinary school database, 4.5% of feline intraocular and adnexal neoplasms (234/5153) were designated as feline ocular posttraumatic sarcoma, a tumor previously demonstrated to be of lens epithelial origin. Similar tumors were seen in rabbit eyes, a bird, and in a dog. All 4 species with lens tumors had a history of either ocular trauma or protracted uveitis. The literature search also revealed cases where lens tumors were induced in zebrafish, rainbow trout, hamsters, and mice by carcinogenic agents (methylcholanthrene, thioacetamide), oncogenic viruses (SV40, HPV-16), and genetic manipulation.
  
  
  CONCLUSIONS
  Our results suggest that lens tumors do not occur in humans. In contrast, after lens capsule rupture, a lens tumor can occur in other species. We hypothesize that a genetic mechanism exists that prevents lens tumors in humans.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin. Electronic address: dalbert@wisc.edu.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Albert
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Paul O
authors.initials: PO
authors.lastname: Phelps
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Krishna R
authors.initials: KR
authors.lastname: Surapaneni
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Thuro
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Heather A D
authors.initials: HA
authors.lastname: Potter
authors.affiliation: McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin; Department of Medical Genetics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ikeda
authors.affiliation: McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin.
authors.forename: Leandro B C
authors.initials: LB
authors.lastname: Teixeira
authors.affiliation: Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Dubielzig
mesh_terms: D000818:Animals; D002415:Cats; D006224:Cricetinae; D016208:Databases, Factual; D004285:Dogs; D005134:Eye Neoplasms / Q000473:pathology* / Q000662:veterinary*; D005260:Female; D052162:Human papillomavirus 16 / Q000472:pathogenicity; D006801:Humans; D007905:Lens Diseases / Q000473:pathology* / Q000662:veterinary*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D017686:Oncorhynchus mykiss; D011817:Rabbits; D013539:Simian virus 40 / Q000472:pathogenicity; D013045:Species Specificity; D046429:Spheniscidae; D015027:Zebrafish