Fui Tin Pang - Hospital Queen Elizabeth II, Sabah, Malaysia- Department of Medical Imaging, Western University, St Joseph’s Health Care London, Ontario, Canada
Kalan Lynn - Department of Medical Imaging, Western University, St Joseph’s Health Care London, Ontario, Canada
Sze Yuen Lee - Department of Radiology, Hospital Segamat, Johor, Malaysia

Background: Fibroadenomas (FAs) are common benign breast tumors which account for ۶۸% of all breast masses. They can be divided into simple and complex FAs. Though unusual, FAs can harbor invasive or in situ carcinomas, as well as high risk lesions such as lobular carcinoma in situ (LCIS) as we present in this case report. Case Presentation: In this case report, we are presenting a rare case of LCIS within a FA with a brief description of presentation, classification and radiological features. Conclusion: Carcinomas within FAs remain a diagnostic challenge. Despite being considered benign, FAs should still be closely monitored by ultrasound (US) as they can still harbor in situ or invasive carcinomas or high-risk lesions, including LCIS. Radiologists should always be aware and consider these as part of their differential diagnosis whenever benign looking masses have atypical features or presentation. The current management of LCIS detected within FA is still similar to LCIS found elsewhere in the breast.

Breast Carcinoma in Situ, Fibroadenoma, Breast Neoplasms