Multicentric lymphoma in a Saint Bernard dog

The Saint Bernard dog aged 9 years was presented with a history of anorexia. On clinical examination, most of the superficial lymph nodes were enlarged. The lymph nodes were soft and painless on digital palpation. The dog was suspected and treated for lymphoma. During the treatment the dog died and was necropsied. On necropsy, the lymph nodes were grossly enlarged 2–5 times, freely movable, firm, bulge oncut surface and with no cortical-medullary demarcation. There was splenomegaly with diffuse enlargement and multiple, pale foci of variable size disseminated in the parenchyma. The mesenteric lymphnodes were also enlarged and showed similar pathological changes as other superficial lymph nodes. Microscopically, lymph nodes showed densely proliferative lymphocytes of variable shape and size, predominantly comprising of lymphoblasts with increased nucleo-cytoplasmic ratio, hyperchromic nuclei and mitotic figures. The above findings were suggestive of lymphoma of multicentric origin.