Molecular cytogenetic analysis of a novel high-grade canine T-lymphoblastic lymphoma demonstrating co-expression of CD3 and CD79a cell markers

We present the molecular cytogenetic analysis of a novel case of canine lym phoma, in a nine-year-old entire male collie cross retriever dog that prese nted with an enlarged prescapular lymph node. A diagnosis of high-grade lym phoblastic lymphoma was made by histological evaluation of fixed lymph node biopsy sections, whilst immunohistochemical analyses demonstrated co-expre ssion of B- and T-cell antigens (CD79a and CD3) by 95% of lymphomatous cell s. Comparative genomic hybridisation (CGH) analysis detected loss of dog ch romosomes 11, 30 and 38 and gain of chromosome 36 within the lymphoma biops y specimen. These findings correlated with direct cytogenetic analysis of t umour metaphases using whole chromosome paint probes representing each of t hese four chromosomes. This study represents the first report of the combin ed application of both direct and indirect cytogenetic techniques for the a nalysis of recurrent chromosome aberrations in canine cancer.