Fine needle aspiration cytology of collagenous spherulosis of the breast.

We present a case of a 45-year-old woman with a benign breast lump in which collagenous spherulosis was an incidental finding. Since collagenous spherulosis has a similar appearance to adenoid cystic carcinoma of breast on fine needle aspiration cytology, the two conditions can easily be confused. The problem of making this important distinction is discussed.