MED-14. Lung cancer presenting as an oral mass.

A 58-year-old African-American male with a 66 pack-year smoking history presented to a dentist with the complaint of bad breath. The patient had also noticed slow bleeding from a growth in his mouth, weight loss, fatigue, and mild pain at the site of the oral lesion. Exam findings were notable for halitosis, a left anterior oral cavity mass involving the gingiva of the lingual surface of the mandible, and a firm, enlarged submandibular lymph node. CT neck and chest revealed an 8.5 X 6 cm mass in the left anterior mediastinum contiguous with the left anterior lung. Another large mass was seen in the right adrenal gland, and a smaller mass was present in the region of the left adrenal gland. Biopsy of the oral mass revealed a poorly differentiated invasive carcinoma with mucosal ulceration. The histology of the oral tumor was not consistent with primary oral cancers. CT-guided biopsy of the lung mass showed a poorly differentiated non-small cell carcinoma with neuroendocrine differentiation. The histologic features and immunohistochemical stains of the lung and oral tumors were similar. The presence of bilateral adrenal masses and the shared pathologic features of the oral and lung tumors support the diagnosis of metastatic non-small cell lung cancer with neuroendocrine differentiation. While primary squamous cell carcinomas comprise the majority of oral tumors, the oro-pharynx can be a site of metastasis for tumors of the lung, breast, prostate, kidney, and thyroid. Oral metastatic tumors usually begin as painless soft-tissue nodules growing from the mandible. Mucosal ulceration and teeth involvement can induce pain as the tumor enlarges. A physician should never assume that a mass in the mouth is a primary oral tumor.

David Redding, MD. Medical University of South Carolina, Charleston, SC.