The material of this study consisted of two pieces of masses which operatively removed from a four year old Collie. Clinically, the dog was quiet and exhausted. The eye conjunctiva and gingiva were pale. The body temperature was 38.2 °C and respiratory rate was 28 beats/minute. The sign of swelling on testicular region was first noticed by the owner but no treatment was considered as defecation and urination were normal except for a slight decrease in the appetite. There were two palpable testicles in the scrotum. Two capsulated masses, the left one in 13x5 cm and the right one in 8x3 cm size, located at extra-abdominally, cranial to scrotum and the both side of the penis was extirpated surgically. The cross-section of these masses was in grey-white colour and there were hemorrhagic foci, 1-2 cm in size. Microscopically, there was mainly diffuse localization, disappearance of tubular structure accumulation of rounded and polyhedral cells. Tumor cells consisted of a thin fibrous tissue and separated by a thin stroma occasionally covered the whole testicle.

In conclusion, the masses investigated by clinical, macroscopic and microscopically and extirpated surgically were diagnosed as polyorchidism (4 testes) and benign seminoma, respectively.