Oral and maxillofacial metastasis of male breast cancer: Report of a rare case and literature review.

Oral and maxillofacial metastatic tumors are uncommon, with the breast, prostate, lung, and kidney representing the most common primary sites. Less than 1% of all breast cancers occur in male patients, and to date, only 8 cases of metastatic breast adenocarcinoma to the oral and maxillofacial region in a male patient have been reported in the literature. An 88-year-old male with previous history of a successfully treated primary breast adenocarcinoma 12 years earlier was referred for evaluation of an oral swelling lasting 6 months. Intraoral examination revealed a 2-cm reddish, pedunculated nodule with a smooth surface located in the left retromolar region. Imaging revealed maxillary sinus involvement. The patient underwent incisional biopsy, and microscopic evaluation revealed invasive tumor islands compounded by malignant epithelial cells, sometimes exhibiting ductal arrangement, which were positive for the estrogen receptor and gross cystic disease fluid protein 15. The final diagnosis was metastatic breast adenocarcinoma. Breast metastases are exceedingly rare in the oral and maxillofacial region of male patients; however, clinicians should consider breast metastasis when evaluating reddish oral nodules in older patients, including men, especially those with a history of malignancy.