Fig. 4: Copy number alterations in paired classic LCIS, pleomorphic LCIS, and invasive lobular carcinoma.

a–d Representative hematoxylin and eosin images of the areas sequenced from paired CLCIS (a), PLCIS (b), and ILC (c) in case P4. The three components shared most copy number alterations, including CCND1 amplification, with three additional changes shared only by PLCIS and ILC (d). e–h Representative hematoxylin and eosin images of the areas sequenced from paired CLCIS (e), PLCIS (f), and pleomorphic ILC (g) in case P5. PLCIS and pleomorphic ILC shared numerous copy number alterations, whereas synchronous CLCIS shared only three of these with PLCIS and ILC (h). Chromosomes are organized from 1 (left) to X (right). Thick arrows indicate large-scale (chromosome or whole-chromosome arm level) copy number alterations; thin arrows, smaller-scale (sub-chromosomal arm) alterations; dotted arrows, subclonal loss or copy neutral loss of heterozygosity; arrowheads, amplification. Black indicates copy number alterations shared among CLCIS, the LCIS variant, and ILC; red, copy number alterations shared between the LCIS variant and ILC; blue, copy number alterations private to a single component.