Use of ultrasonography to diagnose Sertoli cell neoplasia and cryptorchidism in a dog.

: Unilateral cryptorchidism and Sertoli cell tumor in the descended testis were provisionally diagnosed by use of ultrasonography in a 7-year-old Keeshond. The left testis was thought to have degenerated, but ultrasonography of the scrotum did not reveal evidence of testicular or epididymal tissue. The contralateral testis contained a hypoechoic mass believed to be a testicular tumor. Surgery and histopathologic findings confirmed the diagnosis. Ultrasonography of the scrotum and its contents should be considered for use in animals with suspected testicular neoplasia and/or degeneration.