Esophageal plasmacytoma in a dog

: A 14-year-old spayed female dog of mixed breeding had a 3-week history of regurgitation of food occasionally mixed with blood. An esophagram revealed a mass in the caudal portion of the esophagus. The mass was partially removed through esophagoscopy. Evaluation of light microscopy, immunoperoxidase technique, and electron microscopy was consistent with an esophageal plasmacytoma. Surgical excision of the esophageal plasmacytoma was performed. Dogs with esophageal plasmacytoma appear to have a good prognosis.