After reviewing this educational exhibit, the user will have a better understanding of Lobular Carcinoma in Situ (LCIS) particularly: LCIS types and pathological features. Presentation and imaging features Natural history, associated risks, and management recommendations.

LCIS was first described in 1941 by Foote and Stewart as "disease of small lobular ducts and lobules”. Lobular neoplasia is morphologic spectrum including ALH and classic LCIS. LCIS is the proliferation of neoplastic cells that fill and expand more than 50% of acini in terminal duct lobular units (TDLUs). Florid LCIS (fLCIS) is an architectural variant with massive distention of lobule(s), duct extension, and frequently comedonecrosis. Pleomorphic LCI (pLCIS) is an uncommon high nuclear grade variant of LCIS, and is more biologically aggressive than...

IMAGING FEATURES: LCIS is usually incidental, adjacent to calcifications. The most common finding prompting biopsy that yields LCIS is calcifications. Best imaging tools include mammogram which shows grouped amorphous calcifications. MR may show extent of disease, as well as surveillance of the remainder of both breasts. Mammographic Findings LCIS most commonly appear as grouped amorphous or punctate calcifications or, more often, occult on mammography. Less commonly will present as asymmetry, or round mass. PLCIS will show as pleomorphic (most common), round or amorphous calcifications that...

LCIS is a high-risk marker and nonobligate precursor for development of invasive cancer. Surgery is recommended for florid and pleomorphic LCIS. Classic LCIS with concordant low-suspicionimaging can be managed with imaging follow-up and risk-reducing medication. NCCN, ACR advise to consider adding annual screening MR.

Shafik N. Wassef, MD, DABR Clinical Assistant Professor Women's Imaging,Department of Radiology College of Medicine, University of Florida in Gainesville No Conflict of Interest

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