Cytologic features of 22 radial scar/complex sclerosing lesions of the breast, three of which associated with carcinoma: clinical, mammographic, and histologic correlation.

Radial scar/complex sclerosing lesion (RS/CSL) of the breast has become more frequently detected with the increasing performance of mammography as a screening test. The clinical, mammographic, and cytologic features of 22 cases of histologically proved breast RS/CSL, 3 of which associated with carcinoma arising at the periphery of the lesion, were reviewed. Clinical examination and mammography did not show specific features in differentiating RS/CSL from carcinoma of the breast. Cytology of RS/CSL without associated malignant changes was dominated by bland epithelial clusters and bipolar naked nuclei. Apocrine cells, papillary clusters, foam cells, and fibrillary elastoid material were also frequently seen. At the cytologic review, only one case of RS with apocrine adenosis, showing atypical cells, was diagnosed as suspicious. Two of the three cases of CSL with associated carcinoma in situ were cytologically characterized by the presence of single atypical cells. In the third case, characterized by a small tubular carcinoma near to CSL, fine-needle aspiration cytology revealed few tubular clusters without myoepithelial cells. Although cytology of RS/CSL without associated carcinoma does not seem characteristic, in most cases a diagnosis of benignancy can be performed correctly. The application of fine-needle aspiration cytology to mammographic lesions with features suggesting RS/CSL may permit a better planning of these lesions.