Primary splenic diffuse large B-cell lymphoma with multinucleated giant cells in a horse

A diagnosis of a diffuse splenic large B-cell lymphoma with multinucleated giant cells in a 5-year-old mare was made based upon the clinical, pathological, and immunohistochemical findings. The enormous primary splenic mass weighed 51.75 kg. To the best of our knowledge, this is the biggest reported splenic mass and the first case of an equine diffuse large B-cell lymphoma with multinucleated giant cells.