Definition A<unk>  is a type of intraductal papilloma that arises within the lactiferous ducts that are located within the<unk> . Differential diagnosis The microscopic appearance of a<unk>  can be mistaken for carcinoma. Other conditions that have similar symptoms and signs as<unk>  include Paget's disease of the breast, other intraductal papillomas, ductal carcinoma in situ (DCIS), syringomatous<unk>  of the<unk>  and subareolar sclerosing duct hyperplasia. Imaging Lesions of the<unk>  and areola, such as<unk> , may be difficult to image clearly on routine mammogram or ultrasonography.<unk> s can be imaged using magnetic resonance imaging (MRI) and conventional or MR ductogram. Biopsy Once excised, the macroscopic appearance of<unk> s is of a poorly defined nodular mass. The microscopic appearance can be quite bizarre, and may be misinterpreted as a carcinoma.<unk> s usually have a rounded outline at low magnification, and at higher magnification can be seen to consist of a haphazardly arranged mass of proliferating tubular structures composed of epithelial and myoepithelial cells within varying amounts of fibrous stroma. The epithelial cells are usually columnar, but the columnar epithelial cells can undergo apocrine or squamous metaplasia. Mitotic figures and necrosis are not commonly seen.
Nipple adenoma
Sebaceous adenoma
Ceruminous adenoma
Ectopic pancreas
Pancreatic serous cystadenoma
Enteric duplication cyst
Bile duct hamartoma
Gartner's duct cyst