Black esophagus and diabetes: a close relationship.

The black esophagus is a rare clinical entity, down to 0.2% in autopsy series and 0.001-0.2% in series of endoscopies. Although it is an entity that has already been reported in the literature, its etiopathogenesis is not completely known. Different theories have been proposed to clarify their cause. One of these theories makes a hypothesis of a viral infection as the underlying cause; this theory can be seen in the literature extensively, but only two cases were reported. The first case is a case with histopathological confirmation of Herpes virus infection. The second is a case in which vascular deterioration has been the main cause of esophageal necrosis. In both cases, diabetes is the factor that determines a bad evolution of the disease.