Papilloma
From Felipedia
Papilloma virus infections in cats have been reported rarely, and usually occur in the facial region of older cats[1].
Solitary lesions have been reported in North America, Australia and Europe[2]. Histopathologically, they appear similar to equine sarcoids, and have been termed feline sarcoid, but a feline specific virus is incriminated (feline papilloma virus-1). Papilloma virus appears to be more common in immunocompromised cats (concurrent infection with FeLV and FIV has been reported)[3].
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Clinical signs
Papilloma virus infections usually manifest as crusty plaques and secondarily infected ulcers on the face, limbs and trunks. Lesions are often pruritic and self-trauma results in secondary bacterial infections. Multiple, hyperplastic plaques, have been seen in old Persian cats and in other cats, one of which was FIV-positive[4][5]. These lesions, which are sometimes hyperpigmented, occur mainly on the trunk.
An association between feline papilloma virus and multicentric squamous cell carcinoma (Feline bowenoid in situ carcinoma) has been reported[6]. These occur in cats more than 10 years of age and some of them have been reported to be FIV-positive[7]. Clinically they are characterised by papules, nodules and even hyperkeratotic plaques which can become ulcerated. Lesion distribution is multicentric but involves the face, shoulders and limbs[8].
Pathology
The histology of feline fibropapillomas and equine sarcoids is virtually identical, characterized by a fibroblastic proliferation with overlying epithelial hyperplasia and rete ridges. Electron microscopy confirms the fibroblastic nature of the neoplastic cells.
In one study, 12 of a 18 cats were diagnosed with fibropapilloma were less than 5 years old[9]. In all of the feline tumours for which paraffin-embedded material was available and that had amplifiable DNA, papillomavirus DNA was identified by PCR. The nucleotide sequence from the feline tumour was distinct from, but most similar to, bovine papillomavirus type 1. Eleven of the 20 cats had known exposure to cattle and all but 1 were submitted from veterinary clinics in Wisconsin, a state known for its dairy farms. The remaining nine cats did not have confirmed exposure to cattle but may have been exposed unbeknownst to the clinician or owner, i.e., prior to living with the present owner.
Diagnosis
Fibropapilloma and feline sarcoids need to be distinguished from fibrosarcoma, but histopathology is required to confirm this. Feline bowenoid in situ carcinoma have a similar appearance, as do nasal squamous cell carcinoma.
The low incidence of feline cutaneous fibropapillomas is related to the tranmission of the virus from cattle. Cats that have greater contact with cattle, i.e., farm cats, may not be biopsied often. In addition, the molecular techniques for identifying viral DNA in these tumours have only recently become available. Any or all of these factors may contribute to the paucity of reports of feline fibropapillomas[10].
Based on immunohistochemistry, electron microscopy, and molecular tests, the papillomavirus in feline cutaneous squamous papillomas has been considered to represent Felis domesticus papillomavirus-type 1; however, results of DNA sequencing have not been reported. Squamous papillomas appear to affect immunodeficient cats[11]. Two of the older cats with fibropapillomas had concomitant disease (lymphoma in one and feline immunodeficiency virus infection in another) that may well have caused immunosuppression. It seems logical that immunosuppression might play a role in viral oncogenesis and apply to both manifestations of cutaneous papillomavirus infection, i.e., squamous papilloma and fibropapilloma[12].
Treatment
No specific therapy has attempted apart from topical therapy.
Treatment with imiquimod 5% cream showed some response. Most cats (75%) in this trial developed new lesions. New lesions also responded to imiquimod 5% cream in all cats treated. Five cats (41%) had side effects suspected to be associated with the use of imiquimod 5% cream, including local erythema (25%), increased liver enzymes and neutropenia (8%), and partial anorexia and vomiting (8%)[13].
References
- ↑ Munday JS, Hanlon EM, Howe L, Squires RA, French AF. (2007) Feline cutaneous viral papilloma associated with human papillomavirus type 9. Vet Pathol 44(6):924-7
- ↑ Yager, JA & Wilcock, BP (1994) Epithelial tumours. In COlor Atlas and text of surgical pathology of the dog and cat. London, Mosby-Year Book, Europe. pp:292-293
- ↑ Hanna PE, Dunn D. (2003) Cutaneous fibropapilloma in a cat (feline sarcoid). Can Vet J 44(7):601-2
- ↑ Clark, EG (1993) Proc AAVD-ACVD San Diego, pp:56-57
- ↑ Carney HC, England JJ, Hodgin EC, Whiteley HE, Adkison DL, Sundberg J: Papillomavirus infection of aged Persian cats. J Vet Diagn Invest 2:294-299, 1990
- ↑ Guaguere, E & Prelaud, P (2000) A practical guide to feline dermatology. Merial, France
- ↑ Miller, WH, et al (1992) Vet Dermatol 3:177-182
- ↑ Baer, KE & Helton-Rhodes, K (1993) Vet Pathol 30:535-543
- ↑ Egberink HF, Berrocal A, Bax HA, van den Ingh TS, Walter JH, Horzinek MC: Papillomavirus associated skin lesions in a cat seropositive for immunodeficiency virus. Vet Microbiol 31:117-125, 1992
- ↑ Gumbrell RC, Rest JR, Bredelius K, Batchelor DJ, Williamson J (1998) Dermal fibropapillomas in cats. Vet Rec 142:376
- ↑ Yager JA, Wilcock BP (1994) Color Atlas of Surgical Pathology of the Dog and Cat. Wolfe, London, UK, p 292, 1994
- ↑ Sundberg JP, Van Ranst M, Montali R, Homer BL, Miller WH, Rowland PH, Scott DW, England JJ, Dunstan RW, Mikaelian I, Jenson AB (2000) Feline papillomas and papillomaviruses. Vet Pathol 37:1-10
- ↑ Gill VL, Bergman PJ, Baer KE, Craft D, Leung C (2008) Use of imiquimod 5% cream (Aldara) in cats with multicentric squamous cell carcinoma in situ: 12 cases (2002-2005). Vet Comp Oncol 6(1):55-64
