Fig. 2

Histological examples of lobular variants. a CLCIS and CILC (as marked), × 40 magnification. b FLCIS shows the cytology of CLCIS with marked distention of lobular units to form a confluent mass-like lesion, × 40 magnification. c PLCIS with cytological atypia—nuclear pleomorphism with large vesicular nuclei and nucleoli—at least some × 4 the size of lymphocytes; × 600 magnification. d PILC, characteristic discohesion but with high-grade pleomorphic nuclei, with pink, foamy cytoplasm typical of an apocrine phenotype, × 400 magnification. e ILC with signet ring cell morphology, × 200 magnification. f Solid with sheets of classic type cells, × 200 magnification. g ILC showing mucinous/histiocytoid morphology, × 200 magnification. h Alveolar variant with cluster/globular arrangement of at least 20 cells, × 200 magnification. i Mixed ductal-lobular carcinoma, × 200 magnification. The variants of ILC rarely present in pure form and are more likely to occur as mixed lesions with classic type and/or other subtypes, e.g. classic, pleomorphic, and solid. CILC, classic ILC; CLCIS, classic LCIS; FLCIS, florid LCIS; PLCIS, pleomorphic LCIS