Breast – Intraductal Papilloma

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
Breast Cancer Risk Chart

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