Lobular breast carcinoma and its variants

Lobular carcinoma is a special type of breast cancer that shows distinct clinical presentation, morphologic and molecular features, and clinical behavior, and its incidence is rising in recent years. Infiltrating lobular carcinoma (ILC) and its precursor lesions may result in diagnostic difficulties, particularly in the screening settings and their management may be problematic. Variants of lobular carcinoma, such as the pleomorphic variant, although not common, exist and some show differences in behavior warranting their recognition in view of requirements for different management strategies. Here we present a review of lobular carcinomas with particular attention to lobular in situ lesions, epidemiology, subtypes, diagnosis, molecular pathology, and grading of ILC in addition to the clinical behavior, response to therapy, and outcome of patients with ILC.