Rare occurrence of metastasis from lung cancer to the anus: case report and review of the literature.

BACKGROUND: Anal metastases from lung cancer are infrequent, and there are only 10 published cases. Life expectancy is no longer than 1 year after diagnosis because of the typically advanced stage of disease. Treatment, which is typically inefficient, is administered with the intent to cure or avoid local complications. CASE PRESENTATION: We report a case of a patient with non-small cell lung cancer presenting with perianal metastasis mimicking an abscess. CONCLUSIONS: Because perianal masses may be misdiagnosed, patients with lung and other cancers should be evaluated for metastatic disease.