Feline Epithelial Tumors of Skin and Subcutis
Basal cell carcinoma
Papilloma
J. S. Munday; E. M. Hanlon; L. Howe; R. A. Squires; A. F. French (2007) Feline Cutaneous Viral Papilloma Associated with Human Papillomavirus Type 9 Vet Pathol 2007 44: 924-927. [Abstract] [Full Text] [PDF]
Typical papilloma
On skin of head
HPV9 associatedViral plaques (Bowens)
John S. Munday,1 Jeanine Peters-Kennedy (2010) Consistent detection of Felis domesticus papillomavirus 2 DNA sequences within feline viral plaques. J Vet Diagn Invest 2010, 22: 946–949
Abstract. Viral plaques are well recognized skin lesions of cats. They are thought to be caused by papillomavirus infection; however, the causative papillomavirus is uncertain. In the current study, polymerase chain reaction using 2 consensus primer sets and 1 primer set specific for Felis domesticus papillomavirus 2 (FdPV-2) was used to amplify DNA from a series of 14 feline viral plaques. The FdPV-2 sequences were detected in all 14 viral plaques by the specific primers but in only 1 of 14 feline cutaneous trichoblastomas. Papillomavirus DNA was amplified from 8 plaques using the consensus primers. Sequences from FdPV-2 were amplified using the consensus primers from 4 plaques. In addition, 3 plaques contained papillomavirus DNA sequences from Felis domesticus papillomavirus sequence MY1, and a previously unreported papillomavirus DNA sequence was amplified from 1 plaque. As FdPV-2 was consistently present within the plaques, this suggests that this papillomavirus is the likely etiologic agent. Feline viral plaques can undergo neoplastic transformation to Bowenoid in situ carcinomas (BISCs). As FdPV-2 DNA is frequently present within BISCs, this suggests that FdPV-2 induces viral plaque formation and then remains detectible after neoplastic transformation.J. S. Munday, A. F. French, J. Peters-Kennedy, G. M. B. Orbell, and K. Gwynne (2011) Increased p16CDKN2A Protein Within Feline Cutaneous Viral Plaques, Bowenoid In Situ Carcinomas, and a Subset of Invasive Squamous Cell Carcinomas. Vet Pathol March 2011 48: 460-465
AbstractCutaneous viral plaques and bowenoid in situ carcinomas (BISCs) in cats are thought to be caused by papillomavirus (PV) infection. There is evidence that PVs may also cause some feline invasive squamous cell carcinomas (ISCCs). Human oncogenic PVs degrade retinoblastoma (RB) protein, impairing cell cycle control. Loss of RB function also increases p16CDKN2A protein (p16), and increased p16 immunoreactivity within a human oral ISCC indicates that the neoplasm was caused by PV infection. In the present study, p16 immunoreactivity was evaluated in 14 feline viral plaques, 14 BISCs, 7 non–solar-induced ISCCs, 11 solar-induced ISCCs, and 14 trichoblastomas. Increased p16 was present within all viral plaques, BISCs, and non–solar-induced ISCCs. In contrast, little p16 immunoreactivity was visible in the solar-induced ISCCs or trichoblastomas. PV DNA was consistently amplified from viral plaques, BISCs, and non–solar-induced ISCCs. However, just 5 solar-induced ISCCs and 1 trichoblastoma contained PV DNA. Given that both increased p16 immunoreactivity and PV DNA were present within viral plaques, BISCs, and non–solar-induced ISCCs, all 3 may be caused by PV infection. This suggests that feline non–solar-induced ISCCs may develop as a result of neoplastic progression from viral plaques and BISCs. Whether PVs promote this progression is unknown; however, evidence from this study suggests the PV that is associated with viral plaques and BISCs is able to disrupt the p16–RB pathway and therefore could have oncogenic potential. Immunohistochemical detection of p16 appears to be a useful technique to investigate the role of PVs in feline skin disease.
J. S. Munday and D. Aberdein (2012) Loss of Retinoblastoma Protein, But Not p53, Is Associated With the Presence of Papillomaviral DNA in Feline Viral Plaques, Bowenoid In Situ Carcinomas, and Squamous Cell Carcinomas. Vet Pathol May 2012 49: 538-545,
Although papillomaviral (PV) DNA is frequently present in feline cutaneous squamous cell carcinomas (SCCs), a causative association cannot be proven. Oncogenic human PVs cause neoplastic transformation by inhibiting retinoblastoma (pRb) and p53 activity. Therefore, absence of pRb and p53 immunostaining, along with increased p16 immunostaining, indicates a PV cause in some human SCCs. If PVs cause cutaneous feline SCCs, it was hypothesized that a similar immunohistochemistry profile, along with PV DNA, would be detectable. This was investigated using 5 feline viral plaques, 10 Bowenoid in situ carcinomas, 19 SCCs from ultraviolet-exposed (UV-exposed) skin, and 11 SCCs from UV-protected skin. Papillomaviral DNA was amplified by polymerase chain reaction from 30 of 45 lesions. Reduced pRb immunostaining was present in 26 of 45; increased p16 immunostaining was in 30; and p53 immunostaining was in 19. Both reduced pRb immunostaining and increased p16 immunostaining were more frequent in lesions containing PV DNA. In contrast, no association was observed between p53 immunostaining and the presence of PV DNA. SCCs from UV-protected skin more frequently contained PV DNA, reduced pRb, and increased p16 than UV-exposed SCCs. UV exposure was not associated with p53 immunostaining within the SCCs. These results suggest that feline PVs alter cell regulation by degrading pRb. Unlike oncogenic human PVs, there was no evidence that feline PVs degrade p53. These results provide further evidence that PVs may cause feline cutaneous SCCs, especially those in UV-protected skin, and they suggest a possible mechanism of this oncogenic action.Fibropapilloma – feline sarcoid
Feline Sarcoids (ACVP 2000)
176 bp from papilloma E2 gene – a highly conserved gene
19 of 23 positive
1 was tested and was BPV1 and BPV2 50% and 60% homology, and unrelated to other papillomaviruses
John S. Munday, Cameron G. Knight (2010) Amplification of feline sarcoid-associated papillomavirus DNA sequences from bovine skin Vet Derm 21 341-344
Feline sarcoids are uncommon dermal neoplasms that are thought to be caused by papillomaviral (PV) infection. Feline sarcoid-associated PV (FeSarPV) has been consistently detected in sarcoids from North American and New Zealand cats but has not been detected within any other feline sample. This suggests that feline sarcoids may develop due to cross-species infection by a PV from an unidentified reservoir host. While there is some epidemiological evidence to suggest that cattle are the reservoir host of FeSarPV, this PV has never been identified within any bovine sample. In this study both consensus PCR primers and primers specific to FeSarPV were used to investigate the presence of PV DNA within five fibropapillomas and 18 samples of inflammatory skin disease from cattle. Consensus primers amplified bovine PV-2 DNA from four fibropapillomas, but none of the dermatitis samples. However, specific primers amplified FeSarPV DNA from four fibropapillomas and five inflammatory skin lesions. To the best of our knowledge this is the first time that FeSarPV has been detected within any sample other than a feline sarcoid. The ability of FeSarPV to asymptomatically infect bovine skin suggests that cattle are the reservoir host of this PV and feline sarcoids could be the result of cross-species infection of a dead-end host by a bovine PV.
Squamous Cell Carcinoma
Subtypes
There are different types of squamous cell carcinoma.
- Conventional
- Well differentiated
- Poorly differentiated
- Acantholytic
- Clear cell
- Spindle cell squamous cell carcinoma
- Squamous cell arising in viral papillomavirus
Pathogenesis
Cats develop squamous cell carcinoma on their nasal planum and ears (auricle, pinna) expecially. Sunlight exposure is particularly involved. Cats prefer a temperature of 32 degrees C, and will seek out places to warm. Sunlight through a window is a good place. Some SCC contain papillomaviral DNA, which may alter prognosis.
Dos Santos et al (2023) reported on metastasis in 9 of 169 cases (5%). Most were on the nasal planum.
Munday JS, French AF, Gibson IR, Knight CG. The presence of p16CDKN2A protein immunostaining within feline nasal planum squamous cell carcinomas is associated with an increased survival time and the presence of papillomaviral DNA. Vet Pathol 2013;50: 269-273
Dos Santos A, Lamego ÉC, Eisenhardt LM, et al. Prevalence and anatomopathological characterization of cutaneous squamous cell carcinomas with regional and distant metastases in dogs and cats: 20 cases (1985-2020). Vet Comp Oncol. 2023; 21: 291-301.
Acantholytic squamous cell carcinoma
Spindle cell squamous cell carcinoma
Rodriguez et al (2021) reported on 18 cases in cats. 13 were on the pinna, 4 were periorbital, and one was on the muzzle. One metastasised to the local lymph node. SCSCC are dominated by spindle cells. There are often large individual or clusters of cells with large nuclei and large nucleoli. These will be cytokeratin positive, as will some of the spindle cells
Kogame T, Tanimura H, Nakamaru S, Makimura K, Okamoto H, Kiyohara T. Spindle cell squamous cell carcinoma arising in Bowen's disease: Case report and review of the published work. J Dermatol. 2017; 44: 1055-1058.
Rodríguez Guisado F, Suárez-Bonnet A, Ramírez GA. Cutaneous Spindle Cell Squamous Cell Carcinoma in Cats: Clinical, Histological, and Immunohistochemical Study. Vet Pathol 2021; 58: 503-507.