Metastasis of lung adenocarcinoma to the gingiva: a rare case report

Metastatic tumors account for 1% of all oral malignancies. Metastasis to jaw bones is common, particularly in the mandible, rare in the oral soft tissues, and account for only 0.1% of oral malignancies. The majority of metastatic cases (70%) reported in the literature have primary tumors located in the lung, breast, kidney, and colon. Metastasis is a biological complex process that involves detachment from the surrounding cells, regulation of cell motility, invasion, survival, proliferation, and evasion of the immune system. Clinical presentation of metastatic tumors is variable, which may create diagnostic dilemma or may lead to erroneous diagnosis. Metastatic tumors clinically mimic as dental infections. Metastasis to the oral soft tissue from lung cancer, especially gingiva is a rare condition. Metastasis to the gingiva can affect the oral function, speech, and nutrition. Most of the cases in the literature reported that lesion presented in oral soft tissues before the diagnosis of primary tumors. Here we report a case of 62-year-old male patient with metastasis from lung to the gingiva, where the metastasis was detected before primary tumor.