Extranodal marginal zone B-cell lymphomas of the bilateral third eyelids in a dog

Abstract

Extranodal marginal zone B-cell type lymphoma of mucosa-associated lymphoid tissue (MALT) in dogs has similar properties to human low-grade B-cell lymphoma. Both are characterised by a relatively low mitotic rate and a slow manifestation of clinical signs. Primary MALT lymphoma of the third eyelid in canines is very rare. In this case report we describe bilateral MALT lymphoma in a 21-month-old miniature poodle. Histological analysis indicated that the masses were mainly composed of lymphoid cells and lymphoepithelial lesions, a typical feature of MALT lymphoma. Immunohistochemical analysis revealed that the neoplastic cells were positive for CD79α, but negative for CD3. We believe that this case report will facilitate the diagnosis, treatment, and prognosis of canine MALT lymphoma of the third eyelid.