ESR1 and invasive ductal breast carcinoma: The component of neuroendocrine features was nuclear grade 2, estrogen receptor (ER)-positive (< 10%), progesterone receptor (PgR)-negative (< 1%), and human epidermal growth factor 2 (HER2)-negative, while the invasive ductal carcinoma was nuclear grade 3, ER-positive (< 50%), PgR-positive (< 50%), HER2 equivocal (2+), and unamplified on fluorescence in situ hybridization (FISH).