Summary

Basal cell adenocarcinoma (BCAC) is a rare tumour of the salivary glands and often associated with a good prognosis. The present case had BCAC of the parotid gland as the second primary tumour in addition to breast cancer. The patient was a 66-year-old woman who underwent mastectomy due to breast cancer. She then underwent adjuvant chemotherapy and adjuvant hormone therapy. After 4 years of disease-free follow-up, the patient presented with a swelling on the left cheek. The examination of the biopsy specimen revealed BCAC of the parotid gland. The patient then underwent left parathyroidectomy plus left neck dissection. Adjuvant radiotherapy was performed. Despite the therapy, the patient developed four local recurrences within 1 year, and then developed metastasis to the pleura. A swelling in the parotid gland in a patient with breast cancer should be carefully screened for the presence of a second primary tumour.