Lobular Carcinoma in Situ of the Breast
Clinical
- Lobular carcinoma in situ is considered to be a marker of increased risk of invasive carcinoma it can be a precursor lesion
- The increased risk applies to both breasts in most studies
- Recent data suggest 2/3 of subsequent carcinomas are in the ipsilateral breast
- In the past there has been no consensus about management of patients with LCIS in a core biopsy
- A recent study provides data indicating that patients with LCIS in a core should have an excision
- We particularly consider its presence in a core biopsy to be an indication for excisional biopsy in the following situations:
- If there is discordance between the mammographic and pathologic findings
- If another lesion such as atypical ductal hyperplasia is present
- If the lobular nature of the cells is at all equivocal
- If the LCIS is extensive
- In an excisional biopsy:
- We suggest excision with clear margins if florid/extensive, pleomorphic, extensively necrotic or predominantly signet ring
- Otherwise, margins are not relevant if LCIS is the only lesion
- Nevertheless, we generally report margin status to satisfy those who want the information
- The increased risk applies to both breasts in most studies
Relative risk for development of invasive breast carcinoma
- No increased risk
- Non-proliferative fibrocystic change
- Fibroadenoma
- Solitary papilloma
- Slightly increased risk (1.5 to 2 times)
- Proliferative fibrocystic change
- Usual ductal hyperplasia
- Sclerosing adenosis (florid)
- Radial scar
- Complex fibroadenoma (approximately 3 times risk)
- Moderately increased risk (4 to 5 times)
- Atypical ductal hyperplasia (no family history)
- Atypical lobular hyperplasia
- High risk (8 to 10 times)
- Ductal carcinoma in situ, low grade
- Lobular carcinoma in situ
- Atypical ductal hyperplasia, if history of carcinoma in primary relatives
- Very high risk (precise level not known)
- Ductal carcinoma in situ, high grade
