- Found mostly in young (20-40 year old) women
- 40% are related to pregnancy
- On gross pathology, appear as circumscribed but non encapsulated masses
- Microscopically, the contain closely packed, tubular structures that vary little in size
- closely related to fibroadenomas but higher eipthelial : stromal ratio
- Radiologically, they appear as non-calcified, round/oval masses with a well defined margin on mammography and a well-defined hypo-echoic lesion on USS
Although it is recommended that these women are followed up, these masses are completely benign and require no treatment. They may be excised if they are causing local problems.