title: Shope Fibroma in the External Ear Canal of a Domestic Rabbit.
abstract: A 5-y-old, intact, 2.5-kg female domestic rabbit was presented because of blood spatter on the wall of its cage and the toenails of its right hind limb. Physical examination revealed a red, gelatinous mass that spanned the width of the right vertical ear canal. Radiographic images revealed a soft-tissue opacity at the base of the right ear, which was superimposed over the tympanic bulla and extended to the pinna. A CT scan revealed that the soft-tissue mass was within the vertical and horizontal portions of the right external ear canal and extended to the level of the tympanic membrane, with no bony involvement. An incisional biopsy of the mass and subsequent histopathology revealed heterophilic inflammation with bacteria, necrosis, and no evidence of neoplasia. The patient died during anesthesia for removal of the mass at 1 mo after the initial presentation. Necropsy with histopathology of the mass was consistent with Shope fibroma virus in light of the presence of typical intracytoplasmic eosinophilic inclusions. Electron microscopy of paraffin-embedded tissue revealed electron-dense intracytoplasmic structures within neoplastic cells consistent with the diagnosis of Leporipoxvirus. To our knowledge, this report is the first description of Shope fibroma virus invading the external ear canal of a domestic rabbit. Given the results of this case, Shope fibroma should be considered in rabbits presenting with abnormal tissue in the ear canal.
authors.affiliation: Departments of Clinical Sciences, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas;, Email: cikaneksjc@gmail.com.
authors.forename: Shawna J
authors.initials: SJ
authors.lastname: Cikanek
authors.affiliation: Departments of Clinical Sciences, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas.
authors.forename: James W
authors.initials: JW
authors.lastname: Carpenter
authors.affiliation: Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Lindemann
authors.affiliation: Departments of Clinical Sciences, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas.
authors.forename: R M
authors.initials: RM
authors.lastname: Hallman
authors.affiliation: Departments of Clinical Sciences, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas.
authors.forename: David
authors.initials: D
authors.lastname: Eshar
authors.affiliation: Departments of Diagnostic Medicine-Pathobiology, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas.
authors.forename: In Joong
authors.initials: IJ
authors.lastname: Kim
authors.affiliation: Departments of Diagnostic Medicine-Pathobiology, Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas.
authors.forename: Kelli M
authors.initials: KM
authors.lastname: Almes
mesh_terms: D000820:Animal Diseases; D000818:Animals; D004424:Ear Canal / Q000000981:diagnostic imaging; D004427:Ear Diseases / Q000662:veterinary* / Q000821:virology; D017809:Fatal Outcome; D005260:Female; D012776:Fibroma Virus, Rabbit / Q000302:isolation & purification*; D011213:Poxviridae Infections / Q000473:pathology / Q000662:veterinary*; D011817:Rabbits; D011859:Radiography / Q000662:veterinary; D014057:Tomography, X-Ray Computed / Q000662:veterinary; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000473:pathology / Q000635:transmission / Q000662:veterinary*