Cryoglobulinaemia in a Thoroughbred gelding with multicentric lymphoma

A 17-year-old Thoroughbred gelding was presented to the hospital with epistaxis, multiple alopecic skin lesions, firm swelling in the masseter region and acute cellulitis of the right hind distal limb. Epistaxis originated from ulcerative lesions within the nasal passages and nasopharynx. Histopathology results of a skin biopsy revealed necrotising dermatitis. Initial laboratory evaluation included severe leucocytosis with marked hyperproteinaemia and adequate coagulation times. A cryoprecipitate was noted in a refrigerated blood sample in the absence of lipemia. Serum protein electrophoresis yielded inconsistent results depending on sample preparation, suggestive of the presence of cryoglobulins. Evaluation of an uncentrifuged sample revealed a gammopathy, with a peak in the beta 2 globulin fraction. Treatment for vasculitis and dermatitis resulted in little clinical improvement, and the gelding was euthanised. Necropsy revealed multicentric lymphoma with a tropism for perivascular spaces and skeletal muscles.