RESUMO
Studies evaluating histological patterns of lung infiltration by lymphoma in cats are lacking. We evaluated retrospectively the histological patterns of 125 necropsy cases of feline lymphoma collected over a 12-year period. Of the 125 cases, 16 showed lung infiltration (12.8%). Nine cats were female, seven cats were male and all were of mixed breed. Gross lesions observed in the lungs consisted of masses (25%) and nodules (18.7%); however, the majority of cases (56.2%) did not show any gross abnormality. Peribronchial-vascular infiltration (93.7%) was the most frequent pattern, followed by pleural (56.2%), interstitial (50%), nodular (37.5%) and alveolar (12.5%) patterns, but 75% of the cases had more than one pulmonary infiltration pattern. There were 14 (87.5%) B-cell and two (12.5%) T-cell lymphomas. Six cats (37.5%) were positive for feline leukaemia virus and three cats (18.7%) were positive for feline immunodeficiency virus. Diffuse large B-cell lymphoma was the most frequent type, accounting for 56% of all cases.