Are solitary breast papillomas entirely benign?

HYPOTHESIS Solitary breast papillomas are potentially malignant and are associated with a higher risk of breast cancer. DESIGN Retrospective review of all pathological reports containing breast papilloma (1983-2000) and review of selected specimens. SETTING Tertiary, referral, university-affiliated medical center. PARTICIPANTS Ninety-five women with a breast specimen containing a papilloma or papillomatosis. Patients with overt papillary carcinoma without papilloma were excluded. INTERVENTION All histopathological characteristics of the papilloma and the surrounding tissue were noted. The incidence of malignant and other proliferative histopathological findings were analyzed, comparing solitary ductal papilloma cases to multiple papilloma cases. The Fisher exact test and chi2 test were applied for statistical analysis. MAIN OUTCOME MEASURES Surgical removal of solitary ductal papillomas should include margins wide enough to secure removal of any proliferative tissue within or around the papilloma and to enable thorough evaluation of the risk for future breast cancer. RESULTS Solitary papillomas were associated with breast carcinoma in 7 patients (10%) in this series. An additional 9% (n = 6) presented with invasive or noninvasive carcinoma within the papilloma. Atypical papilloma was noted in 6% of patients (n = 4). The risk of associated malignancy was not significantly different between solitary ductal papilloma and multiple papilloma. CONCLUSION Increased risk of breast cancer is associated with all forms of papilloma.