Purpose of review: The incidence of lobular carcinoma in situ and invasive lobular carcinoma of the breast is increasing. Recent data suggest that lobular carcinoma in situ is an indolent precursor for breast cancer, rather than a pure risk factor. This could imply free surgical margins become important. The risk of contralateral carcinoma and of multifocality of invasive lobular carcinoma is higher than for invasive ductal carcinoma. Therefore, the need for mastectomy, or even for preventative contralateral mastectomy is questioned. Conventional mammography or ultrasonography cannot always give useful preoperative information about the extent of lobular cancers. The value of dynamic contrast-enhanced magnetic resonance imaging needs to be established for these patients.
Recent findings: The risk of invasive carcinoma after lobular carcinoma in situ is increased. Invasive carcinoma is usually located at the index point of lobular carcinoma in situ and is of lobular histology. Dynamic contrast-enhanced magnetic resonance imaging can be useful in the detection and preoperative staging of invasive lobular carcinoma. The risk of local recurrence is high in patients with invasive lobular carcinoma. Mastectomy and breast reconstruction could be an option in selected patients. The response to preoperative chemotherapy is worse for invasive lobular carcinoma compared with invasive ductal carcinoma, with a greater need for rescue mastectomy.
Summary: Lobular carcinoma in situ and invasive lobular carcinoma are different entities from ductal carcinoma in situ and invasive lobular carcinoma. Their biological profile should be studied further in order to make the fine tuning of treatment possible.