Oral cyst-like nodule caused by a long standing unusual embedded foreign object: Report of a case

Traumatic implantation of foreign material in the oral mucosa is unusual and may occur. In this article, we report the presence of an unusual foreign object associated with a cyst-like inflammatory response in a 50-year-old male. The patient presented with a painless recurrent soft tissue swelling in the anterior vestibule of maxilla of at least 2-year duration. The lesion was surgically excised and a retained shrapnel-like object within a cyst-like and thick-walled structure was obtained. Histopathologically, the cyst-like structure exhibited a lymphohistiocytic infiltrate in the wall and a luminal synovial metaplasia-like change, predominantly composed of histiocytes. Immunohistochemical stain of CD163 highlighted the histiocytes. The patient stated a history of traumatic implantation of shrapnel fragments in the area that occurred 30 years ago due to an explosion in the Iran-Iraq war.