Lobular carcinoma in situ of the breast within a fibroadenoma. A case report.

BACKGROUND: Fibroadenoma is a benign breast tumor that is effectively treated by local excision. Although uncommon, breast fibroadenoma may harbor breast carcinoma, either in situ or invasive. CASE: We present a 27-year-old woman who presented for the management of an apparently benign mass in the right breast. The clinician and ultrasonographic characters of the mass were indicative of a breast fibroadenoma. A local excision of the mass was performed. Histology showed the presence of LCIS within the fibroadenoma. After a detailed discussion with the patient about the available management options, the conservative approach (which includes local excision/biopsy only and regular follow-up) was preferred.
CONCLUSION: LCIS within a breast fibroadenoma is a rare entity. Carcinomas arising within a fibroadenoma have the same biological behavior as those arising independently and, therefore, their management should be the same. Close surveillance following local excision/biopsy is the preferred management for LCIS within a fibroadenoma.