MKI67 and angiosarcoma: Finally, based on the results of the current study, a diagnostic use of the Ki-67 index is not only that it may be able to distinguish canine hemangiomas from HSAs owing to significantly higher Ki-67 expression in HSAs than in their benign counterparts, as other studies have described [24], but also that it may distinguish hemangioma from well-differentiated HSAs, as has been described in the case of human angiosarcomas [49].