Polyostotic lymphoma in a young dog: a case report and literature review.

An eight-month-old female German shepherd dog had pathological fractures affecting the distal radius and ulna and ribs. Radiographically, there were bilaterally symmetrical osteolytic lesions affecting the metaphyses of multiple long bones, ribs and skull and the dog had splenomegaly. Histologically, the spleen, thymus and bones were infiltrated with large lymphoblastic cells with a high mitotic rate; the diagnosis was lymphoma. Lymphoma primarily affecting bone is an uncommon diagnosis in the dog but it should be considered in young animals with osteolytic lesions affecting multiple bones.