Abstract:

As the level of pet medical care continues to improve, the average life span of domestic animals has been extended. This also led to a significant increase in the detection and diagnosis rates of tumors. For better diagnosis and treatment of canine and feline tumors, it is necessary to understand the characteristics of different tumors and expand their epidemiological database through investigation. Canine testicular tumor is one of the common clinical tumors in male dogs. It generally arises from either the sex cord stromal elements of the gonad or from germ cells. Our study collected 119 canine testicular tumor cases among 2 803 canine tumors sent to our laboratory from multiple hospitals from 2013 to 2021 for retrospective pathological analysis. We listed the gross pathological and histopathological features of four types of canine testicular tumors diagnosed and explored the risk factors for canine testicular tumors. For mixed germ cell-sex cord stromal tumors, which are difficult to diagnose by HE staining, three immunohistochemical markers are combined for accurate diagnosis. The results showed that the detection rate of testicular tumors in male dogs was 10.8%, accounting for 4.25% of all cases submitted for examination. Among them, 28 cases (23.5%) were Sertoli cell tumors, 37 cases (31.1%) Leydig cell tumors, 42 cases (35.3%) seminoma, and 12 cases (10.1%) mixed germ cell-sex cord stromal tumors. Our study provides the latest information on the epidemiology of primary testicular tumors in dogs in China. It confirmed that cryptorchidism is an important risk factor for Sertoli cell tumor and seminoma through statistical analysis of the background information of the affected dogs. In addition, we preliminarily explored possible correlations between breed, cryptorchidism location, and detection rates of different types of testicular tumors.

Key words: canine testicular tumor, histopathology, differential diagnosis