Oral Extramedullary Plasmacytoma Treatment Using a Combination of Marginal Excision and Strontium-90 Therapy in Five Dogs.

Extramedullary plasmacytoma (EMP) is a benign round cell tumor that is most commonly found in cutaneous locations in dogs and occurs less frequently in the oral cavity. They are highly radiosensitive, are distinct from systemic multiple myeloma syndrome and wide surgical excision is typically curative. This report describes five cases of non-invasive oral EMP in dogs treated with a combination of marginal excision and strontium-90 plesiotherapy. All five cases had narrow or incomplete margins on histopathologic evaluation but experienced no recurrence after combination therapy. Plesiotherapy radiation may offer a potential adjunct treatment for non-invasive oral EMP by providing a superficial dose of radiation that complements a less invasive surgical removal. The combination of plesiotherapy and marginal excision may offer an alternative to wide surgical excision for non-invasive oral EMPs.