Immunohistochemical Evaluation of GATA-4 in Canine Testicular Tumors

GATA-4 is a transcription factor expressed in Sertoli cells and less commonly in Leydig (interstitial) cells but not germ cells in adult human beings, cattle, pigs, and mice. We examined GATA-4 in 76 formalin-fixed, paraffin-em bedded canine testicular tumors, including 21 Sertoli cell tumors (SCT), 28 Leydig (interstitial) cell tumors (LCT), 24 seminomas (GCT), and 3 mixed germ cell sex cord-stromal tumors (MGSCT). Our hypothesis was that immunohistochemistry for GATA-4 could discriminate between germ cell and sex cord-stromal tumors of the canine testis. SCTs (21/21) had strong diffuse nuclear and weak and inconsistent cytoplasmic staining. LCTs (27/28) also had strong diffuse nuclear staining and much weaker and granular cytoplasmic staining. GCTs were negative for this marker. Sex cord-stromal cells of MGSCT were also positive. These results indicate that GATA-4 is mainly expressed in sex cord-stromal tumors and not in germ cell tumors of the canine testis.