ESR1 and metastatic carcinoma: In the lymph node, hematoxylin and eosin staining detected a metastatic carcinoma and the immunostaining results were as follows: Cytokeratin (CK)7 (+), CK20 (−), gross cystic disease fluid protein 15 (partial +), estrogen receptor (ER; −) and progesterone receptor (PgR; −).