Introductal papilloma can have varying appearances but characteristically contain an ductal epithelial proliferation on a fibrovascular core with an intact myoepithelial layer. Larger duct lesions are located near the nipple and typically produce a discharge (~80%). Small duct lesions are frequently multiple and located deeper in the breast.
Papilloma are are associated with a slight increased risk for breast carcinoma (1.5-2x increased relative risk). The absence of a myoepithelial layer is not characteristic of a typical papilloma, and likely represents a different papillary lesion.
Breast lesions and risk of developing an invasive carcinoma
![Breast Cancer Risk Chart](https://www.pathmd.com/wordpress/wp-content/uploads/2017/10/Breast_Ca_Risk_Chart-1024x569.jpg)
Reference
Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015. p. 1048-1051