Although the predominant connective tissue component of the female breast is adipose tissue, there are only rare reports of primary mammary lipoblastic neoplasms. Depending upon the rigidity of criteria, between 20 and 30 patients with such neoplasms previously have been recorded.1,2 The large amount of fat in these tumors was distinct from the small foci of mature fat occasionally seen in adenofibromas or in cystosarcomas.
The three women described below had periductal stromal tumors composed predominantly of fat. In two of the tumors the mesenchymal component was liposarcomatous, while the third tumor was a cellular adenofibroma with extensive adipose metaplasia.
Report of Cases
Case 1.—A 41-year-old woman with no history of previous breast disease presented with a freely movable firm mass, 2 cm in diameter, above the nipple of the right breast. The tumor was detected during a routine physical examination, and had not previously been noted by the