Papilloma and Papillary Lesions

Clinical Presentation

Papillomas of the breast can be divided into central and peripheral papillomas. Central papillomas arise in the main lactiferous ducts of the breast in the subareolar region. They may be solitary or, less often, multiple and typically arise in perimenopausal and postmenopausal women, although they have been reported in up to 5% of childhood females presenting with a breast mass. Up to 90% of patients will present with serous or serosanguineous discharge, with the remaining patients presenting with mammographic abnormalities or, less commonly, a palpable mass. Nipple discharge resulting from an underlying papilloma is generally unilateral and hemorrhagic. These lesions are typically less than 1 cm but may be as large as 4 or 5 cm.

Peripheral papillomas have a greater tendency than central papillomas to be multiple and, in fact, peripheral papillomas is a term customarily used by some as synonymous with multiple papillomas . Unlike central papillomas, peripheral papillomas most commonly present as mammographic abnormalities, often with associated calcifications. Microscopic papillomas (1–2 mm) have been referred to as micropapillomas.

In a 1951 study of 108 patients with diagnosed papillomas, 75% of the papillomas were reported to be centrally located. Although data regarding the exact distribution of central and peripheral papillomas are lacking, with the establishment of widespread mammographic screening in the early 1980s peripheral papillomas have been found to be likely as common as or perhaps more prevalent than central papillomas.

Clinical Imaging

Central papillomas are often mammographically occult, although they may appear as a circumscribed subareolar mass with well-defined borders and a lack of stromal distortion. Sonography and/or ductography are the most useful radiographic modalities for visualization of these lesions. Ultrasonography will demonstrate an intraductal mass with an associated dilated duct, a solid mass, or a complex cystic lesion ( Fig. 13.1A to C ). In a study of 51 solitary papillomas, ductograms were positive in 91% of patients and showed a completely obstructing lesion, ductal expansion and distortion, intraductal filling defects, duct ectasia, or wall irregularity.

Peripheral (multiple) papillomas, as noted previously, unlike central papillomas, commonly present as mammographic abnormalities, although they may be radiographically occult ( Fig. 13.2 ). In a study by Rizzo and coworkers, 84% of patients with a diagnosis of papilloma on core needle biopsy presented with mammographic abnormalities and were otherwise asymptomatic. Calcifications are seen in at least 25% of cases.

Gross Pathology

Intraductal papillomas may be grossly occult. Papillomas that are grossly identifiable are often central, involving a large subareolar duct, and appear as a mass within a dilated duct. Subareolar intraductal papillomas can be up to 3 to 4 cm in greatest dimension, although the dimensions of such larger lesions are often attributable to the dilated duct itself rather than the papilloma. Preexcisional core biopsy can particularly result in enlargement of the mass attributable to hemorrhage and/or necrosis ( Fig. 13.3 ).