Mast cell tumor in the mandibular salivary gland in a dog.

A mast cell tumor in the mandibular salivary gland was diagnosed in a 9-year-old English Setter. Dense infiltrating sheets of mast cells were present within the mandibular salivary gland, the medial retropharyngeal lymph node and in two subcutaneous masses on the flank. The salivary gland, lymph node, and masses were excised. The dog was treated postoperatively with the histamine receptor antagonist, cimetidine and the alkylating agent, chlorambucil. The tumor recurred at the angle of the mandible 4 months later and the dog was killed.