A polypoid dermal lesion with histologic, immunohistochemical, and ult
rastructural features of hemangiopericytoma is described. Such tumors,
arising in the dermis, are exceptionally rare, and whereas the tumor
bears some resemblance to meningioma-like tumors of the skin and the w
ell-recognized animal counterpart, canine hemangiopericytoma, it is hi
stologically distinct.