Testicular leiomyosarcoma in an SMP30 knockout mouse

Reports of testicular leiomyosarcoma are extremely rare in the veterinary literature. here we report a case of testicular leiomyosarcoma occurring in a 32-weeks-old male senescence marker protein 30 (smp30) knockout mouse. grossly,a testicular mass completely replaced the right testis. the mass had a diameter of 1.6×0.9cm,and was well-encapsulated and firm. the cut surface showed heterogeneous white and yellow-brownish components with multifocal hemorrhages. microscopically,the mass was composed of interlacing bundles of neoplastic cells characterized by a spindle-shaped appearance with elongated blunt-end nuclei and frequently observed mitotic figures. immunohistochemically,the neoplastic cells showed strong positivity for vimentin and α-smooth muscle actin. finally,present case was diagnosed as testicular leiomyosarcoma in an smp30 knockout mouse. © 2017 pvj.