Skeletal muscle lymphoma in a bullmastiff

A 16-month-old, neutered male bullmastiff was presented for acute onset of massive swelling of the right hind limb. Primary skeletal muscle lymphoma w as diagnosed based on cytopathology, surgical biopsy, and necropsy findings . Cutaneous metastases developed during the hospitalization, and additional metastases were found in the heart and thoracic wall. Primary skeletal mus cle lymphoma is a rare form of lymphoma in dogs and should be considered as a differential diagnosis for acute, soft-tissue swelling of the limb.