Scalp pilomatrix carcinoma as an extra-axial mass. We report the CT, MRI, and angiographic findings in a case of pilomatrix carcinoma that had invaded the temporal bone and presented itself as an extra-axial mass. Even though bone destruction was better shown with CT, the tumor mass with its meningeal and tentorial extension was seen more clearly with MRI. The arteriogram demonstrated a unique vascular supply from the external carotid artery. 