An ultrasonogram (USG) of the neck was done, which was normal and a core needle biopsy of the oral swelling was performed which showed metastatic carcinomatous deposits with pan-cytokeratin (PAN-CK) positivity, estrogen receptor (ER) positivity, and the Ki-67 value was 10% to 20% which was suggestive of breast carcinoma metastasis. Here, ESR1 is linked to breast carcinoma.