US-guided core biopsy was performed and resulted in RSL without atypia. Because of the risk of associated malignancy, excision was recommended.
The spiculated mass was excised and the diagnosis of RSL is confirmed, together with a tiny focus of low grade DCIS.
Top differential diagnoses of RSL:
- tubular carcinoma
- invasive ductal carcinoma (IDC) NOS
- invasive lobular carcinoma (ILC)
- postsurgical scar
RSL shows 1.8 x relative risk of developing invasive breast carcinoma , 2.8 x relative risk if associated with atypia.