Fig. 2: Example of invasive micropapillary carcinoma tumors with intense basolateral HER2 membrane staining and corresponding fluorescence in-situ hybridization images.

a, c Invasive micropapillary carcinoma shows intense and incomplete basolateral membrane staining. b, d Fluorescence in-situ hybridization image corresponding to a and c presented HER2 amplification with clustered HER2 signals, respectively.