Breast carcinoma is the most common in women. However, metastasis to the oral region is rare. Moreover, it usually occurs in the maxillary and mandibular bones. It rarely occurs in the soft tissue.
Case Report
A 66-year-old Japanese woman was referred to a hospital with a chief complaint of swelling in her right buccal region. It started a month before her visit. Doctors detected a hard and mobile mass under her right buccal mucosa. However, the mass was asymptomatic without any abnormal facial appearance. CT showed an apparent and demarcated lesion under the right buccal mucosa and her submandibular lymph nodes were also swollen. A weighted MRI of the buccal mass revealed a low signal on T1 and T2. At the same time, suppression imaging revealed a high signal of T2 fat suppression.
A buccal mass biopsy was performed, and the pathology indicated breast carcinoma metastasis. Additionally, before her visit to the hospital for the buccal mass, she noticed a lump on her left breast. Post buccal mass biopsy, ultrasound showed a mass in the left upper breast. A core needle biopsy confirmed the diagnosis of breast carcinoma and scirrhous carcinoma. Furthermore, PET/CT showed FDG avidity in the right cheek, submandibular area, left breast, axilla, and supraclavicular fossa. Immunochemistry revealed estrogen and progesterone-positive receptor cells. However, there was no amplification of HER2 gene.
Treatment
The surgeons used anastrozole for hormonal treatment because the patient was post-menopausal. After seven months, no palpable mass was seen in the neck and oral region. Moreover, FDG-PET/CT showed a partial response to the primary breast lesion. A complete response was seen of the buccal and submandibular metastasis. Two years after the initial diagnosis and treatment, swelling of the right submandibular lymph node was seen on CT. Fulvestrant treatment initiated at this point, has proven to be effective.
After another two years, the painful submandibular lymphadenopathy reappeared. When doctors did the CT, it showed swelling of the right cheek and bilateral neck lesions. They prescribed a cyclin-dependent kinase inhibitor abemaciclib with fulvestrant. It is being used to date. As of August 2021, the oral and neck lesions have disappeared, and the chest lesions are also controlled.
