Morphoathological description of an extra genital canine transmissible venereal tumor

The transmissible venereal tumor (tvt) is a contagious and sexually transmissible neoplasia of unknown origin. in natural conditions the tumor mainly affects the external genitalia of both male and female dogs. a 6-year old male german shepherd dog,weighing 16 kg was presented for evaluation of a mass on the nasal cavity which the owner had noticed 2 months ago. clinical examination revealed multiple nodular ulcerated lesions of varying sizes from 1 to 3 cm in diameter over the nasal cavity. the tumor mass had a firm consistency,was hyperemic and ulcerated. histopathological examination showed uniform-sized dense cells arranged in solid sheets and clusters interlaced by a little connective-tissue stroma. the cells were round and ovoid,with a moderate amount of cytoplasm that was either clear or finely granular and had a large nuclear/cytoplasmic ratio. on the basis of the clinicopathological findings,this mass was diagnosed as a transmissible venereal tumor.