They do not ever do biopsies on hemangiomas, because of the risk of bleeding and rupture. After an ultrasound, typically your doctor will have you do a CT Scan (with contrast, and hemangioma protocol) or an MRI. A CT or MRI can almost definitively identify a hemangioma since it is a mass of tangled veins vs. a cancerous mass. Biopsies are just not done on these.