Difficult Diagnosis in a Case of Canine Alimentary Mast Cell Tumor

Abstract

An 8-year-old cavalier King Charles spaniel that had not passed feces for 7 days was referred to our hospital. Contrast-enhanced computed tomography revealed a mass in the small intestine and a filling defect of contrast agent in the spleen. Fine-needle aspiration biopsy of the intestinal mass revealed lymphoid cells. Surgery to remove the intestinal mass and spleen was performed on day 19. PCR using DNA isolated from the intestinal mass showed T-cell clonality. A provisional diagnosis of alimentary lymphoma was made, based on T-cell clonality and cytological observation, but the histopathological diagnosis was alimentary mast cell tumor.