Cancer of the mandibular gingiva metastasizing to the small intestine.

Head and neck cancer metastasizing to the small intestine is very rare. Here we report a case of cancer of the mandibular gingiva metastasizing to the small intestine. The patient was an 82-year-old man who had squamous cell carcinoma of the mandibular gingiva staged as T2N2bM0. Two months after surgery, he presented with lower abdominal pain accompanied by signs of peritoneal irritation. Urgent abdominal surgery was performed, during which a crater-shaped perforation was noted on the wall of the ileum. Microscopic findings at this site confirmed a diagnosis of metastatic squamous cell carcinoma in the small intestine from the mandibular gingiva. To our knowledge, this is the first case report of oral cancer metastasizing to the small intestine. If gastrointestinal symptoms appear in a patient with advanced oral cancer, a differential diagnosis of metastasis to the gastrointestinal tract should be kept in mind.