Lipotoma of the breast diagnosed by film and xeromammography.

Five cases of the relatively uncommon intramammary lipoma and 4 cases of the rare adenolipoma were found in more than 5,000 patients who underwent mammography. The mammographic features of the intramammary and paramammary lipomata are given and the characteristic xeroradiographic appearance of adenolipomata is described. The 4 adenolipomata were only visualised by xeroradiography. The reason for these neoplasms being visible on xerograms and not on film mammograms is not clear, but we surmise that it is owing to the 'edge enhancement' phenomenon inherent in the xeroradiographic process. The question whether adenolipomata of the breast are true invasive tumours or mixed neoplasms is discussed.