Mandibular Metastatic Breast Cancer: A Rare Case Report with Diagnostic Challenge.

Jawbone metastatic lesions are a diagnostic challenge because of their rarity and variable clinical, radiographic, and histopathologic characteristics. This paper presents a 57-year-old female with a chief complaint of lower face swelling. Cone beam computed tomography (CBCT) showed a multilocular radiolucency with right angle septa in the left mandibular area with cortical destruction. She had a history of right breast cancer about six years ago. Histopathologic examination revealed sheets of malignant small round cells. Immunohistochemistry (IHC) was only positive for cytokeratin (CK) and GATA3. CA15-3 tumor marker was higher than the normal range. Based on the aforementioned data, the diagnosis of metastatic breast carcinoma was performed. The whole-body and computed tomography (CT) scan showed just involvement in the left mandibular area. The radiographic appearance of metastatic lesions might be misleading, and microscopic sections might be poorly differentiated, therefore, a precise past medical history, IHC staining, and tumor markers are valuable issues in diagnosing oral cavity metastasis.