• ABSTRACT
    • Atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS) represent a spectrum of breast disease referred to as "lobular neoplasia" (LN). Although LN occurs relatively infrequently, it is associated with an increased risk of breast cancer, ranging from a three- to four-fold increased risk with ALH up to an eight- to ten-fold increased risk with LCIS. Initially regarded as a direct precursor to invasive lobular carcinoma, LCIS used to be treated by mastectomy. Subsequent studies demonstrating that the risk of invasive disease was conferred bilaterally and that subsequent cancers were of both the ductal and lobular phenotype led to the acceptance of LCIS as a marker of increased risk rather than a true precursor. Today, a diagnosis of LCIS remains one of the greatest identifiable risk factors for the subsequent development of breast cancer. As such, patients are offered one of three options: (1) lifelong surveillance with the goal of detecting subsequent malignancy at an early stage; (2) chemoprevention; or (3) bilateral prophylactic mastectomy. Paralleling changes in the management of invasive breast cancer, trends in the management of LCIS have moved toward more conservative management. However, we have made little progress in understanding the biology of LCIS and therefore remain unable to truly optimize recommendations for individual patients.