Unsupervised hierarchical clustering of genome copy number profiles measured for 21 pleomorphic lobular carcinoma in situ (PLCIS) and 20 classic LICS (CLCIS). Green indicates increased genome copy number, red indicates decreased copy number, and yellow indicates amplified copy number. The bar to the left indicates chromosome location with chromosome 1pter at the top and 22qter and X at the bottom. The top color bars indicate types of LCIS. In the upper bar, apocrine PLCIS is blue and non apocrine PLCIS is green. In the lower bar, CLCIS is green, and PLCIS is blue. Four clusters emerge: Clusters 1 and 4 are enriched with CLCIS, while cluster 2 with nonapocrine PLCIS and cluster 3 with apocrine PLCIS. Note that cluster 3 is characterized by genome amplification and shows the highest genome instability.