Fig. 2: Histologic images of patterns of residual tumor.

a In this case there is a single, circumscribed focus of residual invasive carcinoma with a patchy associated lymphoid infiltrate. This pattern of residual tumor corresponds to that depicted in Fig. 1a. b In this case the residual tumor is composed of nests of tumor cells, separated by treatment-related fibrosis, but the tumor cell nests are present in a confined, circumscribed area. This pattern of residual tumor corresponds to that depicted in Fig. 1b. c In this case there are widely scattered residual tumor cells, in small clusters and as single cells, broadly distributed across a fibrotic tumor bed. This pattern corresponds to that depicted Fig. 1d.