Duct papilloma is benign lesion occurring in the lactiferous sinuses of the nipple
Large duct papillomas are usually solitary but small duct papillomas are multiple
Clinical presentation –
Large duct papillomas – serous discharge from nipple and mass in the central region below the nipple
Small duct papillomas – Small palpable masses or calcifications or densities on mammogram
Morphology
Gross – Solitary small mass measuring less than 1cm in diameter
Microscopy –
Papillomas are composed of multiple branching papillae with fibrovascular core growing in dilated duct which is lined by benign ductal epithelial cells and myoepithelial cells
Epithelial hyperplasia and apocrine metaplasia can be present
Can be distinguished from intraductal papillary carcinoma which shows cells having pleomorphism, atypical mitotic figures and absence of myoepithelial cells.