Diagnosis, Management, and Long-Term Outcome of Esophageal Plasmacytoma in a Dog

A nine-year-old, 10.5 kg, female-spayed Poodle-mix dog presented with a five-day history of vomiting and regurgitation. Thoracic radiographs revealed an area with increased opacity within the esophageal lumen. A ductal esophageal lesion with intraluminal extension and mild left axillary lymphadenopathy were detected on computed tomography. Esophagoscopy revealed a large vascular, obstructive mass with a smooth surface, in the mid part of the esophagus. Endoscopic biopsies were collected, and histopathologic findings were consistent with an inflammatory polyp. Surgical excision of the mass via sternotomy was performed and the mass was sent for histopathologic evaluation. Histopathological examination of the mass revealed an esophageal plasmacytoma with perivascular amyloid deposition, which was confirmed by immunohistochemical staining. There was no evidence of regrowth until 18 months after surgical removal, when evidence of regrowth was identified. The dog had only one episode of vomiting and regurgitation which was resolved after symptomatic treatment.