Epidemiological, pathological and immunohistochemical aspects of 125 cases of feline lymphoma in Southern Brazil

Abstract

A retrospective study compiling cases of feline lymphoma diagnosed during 12 years (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016) in Southern Brazil was performed. A total of 125 cases of lymphoma diagnosed in cats were reviewed, and information including age, breed, sex and tumour topography were collected. FeLV and FIV immunohistochemical tests were performed, as well as immunophenotyping of lymphomas. The alimentary form represented the most common presentation (42/125), followed by mediastinal lymphoma (35/125). Out of 125 cases, 79 presented positive retroviral immunostaining in tumour tissue (52 FeLV alone, 14 FIV alone and 13 presented FIV and FeLV co-infections), 66/125 of the cases were of T-cell origin and 59/125 of the cases were of Bcell origin. The median age of cats with T-cell lymphoma was 120 months (10-240 months), and 60 months (6-204 months) for cats with B-cell lymphoma. The most frequent alimentary tumour presentation was the enteropathy-associated T-cell lymphoma (type 1), and the major type of mediastinal tumour observed was diffuse large B-cell lymphoma. Considering only mediastinal and alimentary lymphomas (n = 77), the prevalence of mediastinal lymphoma in FeLV-positive cats was 2.21 times higher than the prevalence of this type of tumour in FeLV-negative cats (P = .036).Mediastinal lymphoma was more frequently observed in younger cats, and the prevalence of mediastinal tumours in these animals was 3.06 times higher than the prevalence of this tumour form in old cats (P = .0125). The present study indicates that retroviral infections still play an important role in the development of feline lymphomas in southern Brazil.

Ophthalmopathologic characterization of multicentric or metastatic neoplasms with an extraocular origin in dogs and cats

“…Most of the cats of the present study had T‐cell phenotype lymphomas (67%), although the literature presents conflicting results with regard to the neoplastic lymphocyte phenotypes in FeLV‐associated lymphomas 16,28‐30 . Although recent studies have shown a decrease in lymphomas associated with FeLV, due to efficient vaccination protocols targeting this virus, 29 other studies conducted in Brazil through serological, molecular, and immunohistochemical analyses have established a higher prevalence of FeLV associated with lymphomas 31‐34 …”

Tumor prevalence in cats: experience from a reference diagnostic center in Mexico City (2006-2018)

“…In Brazil, studies confirmed an important presence of multicentric and/or mediastinal lymphoma in cats, with a correlation with the prevalence of feline leukemia virus (FeLV). 37,38 Since data regarding the prevalence of this viral pathogen in Mexico is limited, FeLV cannot be discarded as a potential cause of the high frequency of mediastinal and multicentric cases reported in this study. The mean age of presentation of lymphoma was 7.8 ± 5.2 years, similar to that observed by Graf et al who found this neoplasm to be the most frequent tumor type in young cats.…”

Primary pulmonary diffuse large B-cell lymphoma associated with feline leukaemia virus infection in a young cat

“… 17 – 21 FeLV infection in feline lymphoma can be demonstrated by IHC staining of FeLV capsid p27 and envelope gp70. 10 , 20 , 22 , 23 On IHC, FeLV-positive cats are immunohistochemically regarded as productively FeLV-infected cats. 22 Moreover, 87% (34/39 cases) of lymphomas occurring in the upper airways such as the nasal cavity and nasopharynx have been found to be of the B-cell type, and in 62% of these cases (n = 21/34) FeLV p27 and/or gp70 were detected on IHC examination.…”