Metastasis of breast carcinoma to mandibular gingiva.

Metastatic tumours to the oral region are rare but more often involve the jaws rather than the oral soft tissues. In this report, an infiltrative ductal carcinoma of the breast that metastasised to the mandibular gingiva is presented. The patient consulted her dentist for what she thought was a dental abscess in the bicuspid region of the lower left jaw. However, her dentist referred her for a specialist opinion of the lesion. The patient's medical history revealed that she had undergone a breast 'lumpectomy' 1 year previously. A provisional diagnosis of primary or metastatic malignancy was made, and a biopsy was performed. Microscopically, the lesion showed features of a poorly differentiated infiltrative ductal carcinoma. Subsequent microscopic review of the primary lesion also showed a poorly differentiated infiltrating ductal carcinoma of the breast identical to the features observed in the metastatic lesion.