The circulatory disturbances of the tongue are extremely rare because of its rich blood supply [2]. Lingual artery, ascending pharyngeal artery and external facial artery form a good network that supplies the tongue; hence, gangrene of the tongue is unlikely [1].
Gangrene of the tongue is a rare phenomenon, less than 30 cases have been reported in the literature. An important cause of gangrene of the tongue is giant cell or temporal arteritis [3]-[5]. This form of gangrene can be confirmed by the histopathology report. As histopathology of the specimen was non-specific in our patient, this was ruled out to be the cause.
Other reported causes of the gangrene are intra-aortic balloon pump for cardiogenic shock [6], self-application of an elastic rubber band [7], atherosclerotic arterial occlusion [1]. These have been reported merely as sporadic case reports. None of these could be a possibility in our patient.
As the patient was mentally retarded, we were unable to glean the exact history. Based on the history of self-inflicted trauma to the tongue, we speculate that it may be the cause for the gangrene to occur. There may be impairment to the venous drainage, which appears to develop only as a consequence of an extensive posttraumatic or inflammatory edema of the floor of the mouth and tongue base [2]. This impairment of venous drainage may result in a large acute swelling of the tongue, or to ischemia carrying a painful tongue swelling, and possibly tongue necrosis [2]. However, we do agree that exact etiology was not known.
To conclude, gangrene of the tongue is a rare phenomenon. The treatment must be based on the etiology; however, if the etiology is not known, it must be symptomatic.