Fig. 2

Gross and histopathological findings of the tumor. A Gross findings. The paratesticular tumor (white arrows) is well-circumscribed, detached from the testis (A). Cut surface shows heterogeneous greyish-white in color. B Microscopically, tumor lesion shows proliferation of short spindle cells in a diffuse or perivascular pattern, accompanied by collagenous stromal fibers and dilated vascular channels. No nuclear atypia or mitotic figure is shown. C Myoid stromal areas are focally seen with hypocellularity. D–H Immunohistochemical findings. Short spindle cells are positive for alpha-smooth muscle actin (D), CD34 (E), estrogen receptor (F), and progesterone receptor (G) and negative for desmin (H). Vascular walls and endothelial cells are also positive for alpha smooth muscle actin and CD34 and desmin, respectively