SMN1 and neoplasm: The solid type has tightly packed smooth muscle fibers and many small blood vessels, while the cavernous type contains large, dilated blood vessels and less smooth muscle. As in our case, venous-type angiomyoleiomyomas are composed of thick vascular walls with intravascular smooth muscle [14,15]. Matsuyama et al. analyzed 122 cases of angiomyoleiomyomas (74 solid, 37 venous, and 11 cavernous types) and showed that all tumor cells were positive for SMA, with 51.4% of venous types showing diffuse positivity for desmin [17].