Spindle cell lipoma breast.

Spindle cell lipoma, which usually arises in the soft tissues, is rare in breast and is difficult to differentiate from primary mammary spindle cell tumor. Here, we present the case of a 48-year-old woman with a 3-cm, solitary, well-circumscribed and nontethered mass lying deep within the tissue of left breast, incidentally detected on routine mammography. The spindle cells proved to be immunoreactive to CD 34, but nonreactive to desmin and smooth muscle actin.