Lipomatous pseudomass of the breast: diagnosis suggested by discordant palpatory and mammographic findings.

Focal fat collections or lipomas in the breast occasionally present as dominant palpable masses. A retrospective review was done of tissue obtained from 14 breast biopsies performed on the basis of palpatory findings; the specimens consisted almost entirely of fat. Preoperative mammograms were available in nine of these women and all showed the breasts to be composed largely of fat. In three patients there was virtually complete replacement of breast tissue by fat. In selected patients with fatty replacement of breast parenchyma, discordant palpatory and mammographic findings should suggest the diagnosis of a fatty mass or pseudomass and possibly obviate biopsy for purposes of tissue diagnosis.