Benign proliferation of ductal epithelial cells supported by a fibrovascular core.
Grows within a major lactiferous duct, typically in the subareolar region.
Histology: Papillary fronds lined by both epithelial and myoepithelial cells. The presence of the myoepithelial layer is a key feature of a benign lesion and distinguishes it from papillary carcinoma.
Clinical features
Most common cause of pathologic (spontaneous, unilateral) nipple discharge.
Discharge is classically bloody or serosanguineous.
Typically presents in premenopausal women (age 40-50s).
Usually a solitary, small (<1 cm) lesion.
Often not associated with a palpable mass.
Diagnostics
Core needle biopsy
Indication: all patients with suspected intraductal papilloma
Findings
Papillary structure with fibrovascular core covered by both epithelial and myoepithelial cells
Peripheral papillomas may be associated with cellular atypia, DCIS, or invasive breast cancer.
