Multicentric diffuse large B-cell lymphoma with dural involvement in a nursery piglet.

Lymphoma is the most frequently diagnosed neoplasm in pigs, predominantly of B-cell origin. Multicentric forms commonly affect the lymph nodes, spleen, liver and kidneys. This report describes a case of a multicentric diffuse large B-cell lymphoma with dural involvement in a 70-day-old nursery piglet presenting with hindlimb paralysis. Necropsy and histological examinations revealed nodular thickening of the meninges of the brain and sacral spinal cord, as well as adjacent paravertebral ganglia, by proliferations of large neoplastic lymphocytes. The same neoplastic cells infiltrated the mesenteric, inguinal and mediastinal lymph nodes, in addition to the spleen, liver and kidneys. Immunohistochemistry confirmed B-cell lineage, with cytoplasmic and membrane immunolabelling for CD20 and absence of labelling for CD3. To the authors' knowledge, this is the first reported case of a multicentric lymphoma in a domestic pig with concurrent dural involvement.