Parotid Gland Metastasis of Breast Cancer: Case Report and Review of the Literature.

BACKGROUND: Parotid gland metastasis in breast cancer is extremely rare, and only 14 cases have been reported between 1982 and 2010. CASE REPORT: A 67-year-old female patient was diagnosed with invasive lobular carcinoma of the left breast. Although clinical staging was T1N3M1 (stage IV), the tumor experienced a complete response to chemotherapy. We therefore performed a mastectomy followed by radiotherapy, and continued administration of trastuzumab. However, 11 months later, the patient complained of a swelling in the left parotid gland. Histology following a partial parotidectomy revealed a parotid gland metastasis from the breast. CONCLUSION: Treatment with capecitabine in addition to trastuzumab, which is one of the strategies applied in HER2-positive breast cancer, was effective in our patient. Analysis of the 14 cases of parotid gland metastasis from the breast reported between 1982 and 2010 revealed that the metastasis may occur not by direct lymphatic but by hematogenous spread.