Testicular interstitial cell tumor with disseminated cutaneous metastasis in a dog

Background: Although testicular tumors commonly develop in the genital tract of dogs, only few studies have reportedabout metastatic testicular tumors in dogs to date. Therefore, the present study aimed to describe the gross, histopathological, and immunohistochemical findings in a dog with metastatic interstitial cell tumor.Case: A 6-year-old male Beagle underwent clinical examination due to enlargement of the left testicle and nodules inthe skin of the left inguinal region and of the scrotum. The left testicle was cryptorchid (inguinal), and the right testiclewas intrascrotal. Both testicles and affected skin fragments were surgically removed. The right testicle was normal insize and did not exhibit gross changes. However, the left testicular parenchyma had been completely replaced by a firm,grayish-to-white neoplastic mass with an irregular surface. The inguinal and scrotal skin fragments were thickened by theneoplastic masses. Histologically, the left testicular parenchyma was completely obliterated by a neoplastic mass consistingof round-to-oval and polygonal cells. The neoplastic cells generally had abundant eosinophilic cytoplasm with indistinctcell limits. The nuclei were round and small, with aggregated chromatin. However, some cells exhibited high degrees ofatypia and pleomorphism and large nuclei with granular chromatin. Mitotic figures were observed at high frequenciesof up to 11 per high-power field (400×). The mass in the left testicle was diagnosed as malignant interstitial cell tumor.The sections of the inguinal skin and scrotum presented with neoplastic cells similar to those observed in the left testicle,which is consistent with the metastasis of the malignant testicular interstitial cell tumor. On the basis of necropsy, multiple cutaneous and subcutaneous nodules were randomly distributed throughout the body, primarily in the prepuce, head,and limbs. Histological evaluations of the skin nodules...

Testicular interstitial cell tumor with disseminated cutaneous metastasis in a dog

Background: Although testicular tumors commonly develop in the genital tract of dogs, only few studies have reportedabout metastatic testicular tumors in dogs to date. Therefore, the present study aimed to describe the gross, histopathological, and immunohistochemical findings in a dog with metastatic interstitial cell tumor.Case: A 6-year-old male Beagle underwent clinical examination due to enlargement of the left testicle and nodules inthe skin of the left inguinal region and of the scrotum. The left testicle was cryptorchid (inguinal), and the right testiclewas intrascrotal. Both testicles and affected skin fragments were surgically removed. The right testicle was normal insize and did not exhibit gross changes. However, the left testicular parenchyma had been completely replaced by a firm,grayish-to-white neoplastic mass with an irregular surface. The inguinal and scrotal skin fragments were thickened by theneoplastic masses. Histologically, the left testicular parenchyma was completely obliterated by a neoplastic mass consistingof round-to-oval and polygonal cells. The neoplastic cells generally had abundant eosinophilic cytoplasm with indistinctcell limits. The nuclei were round and small, with aggregated chromatin. However, some cells exhibited high degrees ofatypia and pleomorphism and large nuclei with granular chromatin. Mitotic figures were observed at high frequenciesof up to 11 per high-power field (400×). The mass in the left testicle was diagnosed as malignant interstitial cell tumor.The sections of the inguinal skin and scrotum presented with neoplastic cells similar to those observed in the left testicle,which is consistent with the metastasis of the malignant testicular interstitial cell tumor. On the basis of necropsy, multiple cutaneous and subcutaneous nodules were randomly distributed throughout the body, primarily in the prepuce, head,and limbs. Histological evaluations of the skin nodules...(AU)