Lymphangiomatosis of the systemic skin in an old dog

A 13-year-old, neutered male miniature dachshund was presented with a one-month history of bilateral symmetrical swelling in the pinnae and carpal, cubital and tarsal joints, and swelling in the tail. The lesions were histopathologically characterized by multiple dilated lymphatic vessels lined by a single attenuated layer of endothelial cells. The subcutis was predominantly involved. A number of spindle-shaped cells lining the irregular vessels were observed. Morphological atypia was not evident in these cells. Immunohistochemical analyses revealed that the proliferating endothelial cells were positive for factor VIII-related antigen and CD31. Based on the clinical presentation and histopathological features, the dog was diagnosed with lymphangiomatosis. Treatment with anti-inflammatory prednisolone improved the symptoms.