## Overview Cutaneous lymphosarcoma is a malignant tumor of lymphocytes that primarily involves the skin. It is the most common external form of lymphoma in horses and presents as multiple firm nodules. The cutaneous form generally carries a better prognosis than internal forms and may respond to corticosteroid therapy for extended periods. ## Causes Unknown. Immune dysregulation is suspected; no definitive viral cause has been established in horses. It is not contagious. ## Diagnosis Biopsy and histopathology of skin nodules confirm the diagnosis. Staging evaluates for internal involvement. ## Treatment Corticosteroids often induce partial or complete remission of skin lesions. Chemotherapy protocols are used in some cases. Supportive care maintains quality of life. ## Recovery and Prognosis Guarded to fair for the cutaneous-only form; survival of one to several years is possible. Internal involvement worsens the outlook substantially. ## Prevention None.
multiple firm skin nodules; variable size; possible ulceration; weight loss or other systemic signs if internal disease is present
## Overview Cutaneous lymphosarcoma is a malignant tumor of lymphocytes that primarily involves the skin. It is the most common external form of lymphoma in horses and presents as multiple firm nodules. The cutaneous form generally carries a better prognosis than internal forms and may respond to corticosteroid therapy for extended periods. ## Causes Unknown. Immune dysregulation is suspected; no definitive viral cause has been established in horses. It is not contagious. ## Diagnosis Biopsy and histopathology of skin nodules confirm the diagnosis. Staging evaluates for internal involvement. ## Treatment Corticosteroids often induce partial or complete remission of skin lesions. Chemotherapy protocols are used in some cases. Supportive care maintains quality of life. ## Recovery and Prognosis Guarded to fair for the cutaneous-only form; survival of one to several years is possible. Internal involvement worsens the outlook substantially. ## Prevention None.
multiple firm skin nodules; variable size; possible ulceration; weight loss or other systemic signs if internal disease is present