Parotid gland: an unusual site of breast cancer metastasis

Parotid gland metastases from breast cancer are an extremely rare and unusual event with a limited number of cases recorded in the literature. A 71-year-old woman with a history of ductal adenocarcinoma of the left breast presented to the maxillofacial clinic with an asymptomatic swelling of the left parotid gland. The presentation occurred 21 years after she underwent treatment for recurrent breast cancer. Investigations led to the diagnosis of a breast cancer metastasis which was oestrogen receptor and progesterone receptor positive and negative. Positron emission tomography scan confirmed this as a solitary metastasis. She was treated with aromatase inhibitors and a stable clinical response was observed on follow-up. Surgical intervention was avoided with its potential complications such as facial nerve injury. Metastasis from breast cancer to the parotid gland is a very rare phenomenon. However, in a patient with previous breast cancer, it should be considered as a possible differential diagnosis.