This is a very interesting case. The pictures are not very clear. However, from the pictures we can see it is a solid tumor with irregular shaped pink vascular proliferation. There are numerous mildly dilated vascular spaces lined by bland-looking plump cells. My differential diagnosis includes littoral cell angioma, hemangioendothelialoma or others. I am favor the first. Immunohistochemical study will be very helpful. Littoral cell angioma will be positive for CD31, CD34, CD68 and lysozyme, occasionally also positive for S-100. For the hemangioendothelialoma, the only positive markers are the vascular markers, CD31, CD34 and factor 8.
Hopefully it is helpful.