Abstract
A 6-year-old castrated male Labrador Retriever was presented with lymphadenopathy of the right submandibular lymph node. Abdominal ultrasound revealed a hypoechoic splenic mass and sublumbar lymphadenopathy. The right submandibular lymph node lesion was identified as T-cell-rich B-cell lymphoma, characterized by a mixed cell population with large neoplastic B cells(CD20 and CD79a positive)scattered among numerous small non-neoplastic T cells(CD3 positive)and histiocytes(CD18, MHC class Ⅱ and Iba-1 positive). Cytologic evaluation showed tumor cells invading into the spleen and intra-abdominal lymph nodes. The dog received chemotherapy, but it did not respond sufficiently to the treatment and died 54 days after the initial presentation.
