ESR1 and neoplasm: IHC revealed that the tumor cells showed diffuse and faint EMA positivity with a delicate bipolar staining pattern (Fig. 3A), focally positive staining for MUC4 (in less than 10 % tumor cells)(Fig. 3B), claudin-1(in 10 %-15 % tumor cells) (Fig. 3C) and CD34 (in less than 5 % tumor cells with a similar staining pattern with EMA)(Fig. 3D), and negative staining for GLUT1, S100 protein, estrogen receptor, progesterone receptor, DOG1, smooth muscle actin (SMA), HMB45 and STAT6.