CASE REPORT: UNILATERAL ECTOPIC TESTIS IN THE TUNICA ALBUGINEA CONCURS WITH EPIDIDYMAL HYPERPLASIA IN THE ATROPHIC TESTIS IN A DOG

Abstract

A 10-year-old male Fox Terrier presented with two descended testes of different sizes. The left testis was normal, while the right one was atrophic. The tunica albuginea (TA) of the right testis was distributed with brown spots of less than 1[Formula: see text]mm in diameter, and was microscopically determined to be ectopic testis which consists of Leydig cell adenoma, primitive seminiferous tubules (STs), intratubular seminoma, and reduplication of arterioles. At the junction of the TA with the spermatic cord, units of testis primordia were present. The STs of the remaining atrophic (not ectopic) right testis were populated not by germ cells but by ciliated pseudostratified cells mimicking those of the epididymis, as supported by the immunohistochemistry results. During the adaptation process, multiple smaller tubules combined into fewer but larger less convoluted tubules. This is a case of concurrent ectopic testis and arterial malformation in the TA with hypoxia, subsequent testicular atrophy, and epididymal hyperplasia in a dog.