Mammary arteritis mimicking cancer. Case report.

Giant cell arteritis and polyarteritis nodosa are systemic diseases which rarely involve the breasts. Two cases are reported in which breast masses, clinically suspected to be malignant, were found to be isolated vasculitis--bilateral giant cell mammary arteritis in a 67-year-old woman and isolated mammary polyarteritis nodosa in a 45-year-old woman. Vasculitis should be considered in the differential diagnosis of breast masses.