Paget's disease of the breast: clinical, imaging and pathologic findings: a review of 16 patients.

Objectives: To determine the clinical, imaging and pathological findings of Paget's disease of the breast.

Materials and methods: Approval by Institutional Review Board was granted and informed consent was waived. Retrospective review of the pathological diagnosis of 2,361 women with breast carcinoma between January 2004 and April 2010 revealed 27 patients with Paget's disease of the breast. The clinical, mammographic and ultrasonographic images were retrospectively reviewed.

Results: The prevalence of Paget's disease of the breast was 1.14% of all breast carcinoma at this institution. Of the 27 patients with Paget's disease, only 16 had imaging studies and this group constituted the basis of this study. All 16 patients were women, with ages ranging from 36-68 years (mean age 50.31 years). Eleven patients presented with clinical findings suggestive of Paget's disease of the breast. Seven of these 11 patients also had associated palpable mass(es). Four patients presented with a palpable mass alone and one presented with bloody nipple discharge alone. Mammography was performed in all 16 patients and ultrasonography (US) in 15 patients. Of the 16 mammographic studies, two were negative. Of the 15 US studies, three were negative. Of these three negative US studies, two also had negative mammography and one had pleomorphic microcalcifications on mammogram. US was helpful in detecting multifocality in two patients. Mammography was 100% positive in patients who presented with palpable breast mass(es) and bloody nipple discharge, but 50% positive in patients who had clinically suggestive Paget's disease alone. Almost all patients (15/16) had underlying breast malignancies. Seven patients had multifocality or multicentricity. Modified radical mastectomy was performed in 13 patients, simple mastectomy in two, and wide local excision in one patient. Pathological findings were ductal carcinoma in situ (DCIS) (n = 3), invasive ductal carcinoma (IDC) (n = 10), metaplastic carcinoma (n = 1), invasive lobular carcinoma (ILC) (n = 1), and only Paget's disease of the nipple without underlying breast carcinoma (n = 1).

Conclusion: Patients with Paget's disease of the breast have a high incidence of an underlying breast carcinoma. Most of the patients in this study presented late and were more likely to have positive mammograms. Mammography should be performed to identify the underlying breast carcinoma. Those who have only nipple areolar changes and no palpable mass have less positive mammography and less invasive carcinoma.