Radial scar, a sclerosing ductal breast lesion characterized by an irregular stellate pattern of epithelial proliferation around a central fibroelastic core, may be confused histologically with scirrhous carcinoma of the breast. Mammographic features used to distinguish these two entities were found unreliable in a retrospective review of 255 consecutive stellate lesions. Of 73 nonpalpable carcinomas, fourteen (19%) had radiographic features of radial scar. Only the presence of microcalcifications in 11 of those patients helped the authors distinguish carcinoma from radial scars. Four of nine biopsy-proved radial scars had a dense central region, simulating the appearance of scirrhous carcinoma. Stellate lesions with radiolucent centers should be considered suggestive of carcinoma, particularly if associated with microcalcifications.