Uncommon, overlooked and underreported causes of upper gastrointestinal bleeding

Upper gastrointestinal bleeding (UGB) is a potentially fatal consequence of digestive disorders. There is a wide range of rare causes for UGB that can lead to misdiagnosis and occasionally catastrophic outcomes. The lifestyles of those who are afflicted are mostly responsible for the underlying conditions that result in the hemorrhagic cases. The development of a novel approach targeted at raising public awareness of the issue and educating the public about it could significantly contribute to the elimination of gastrointestinal bleeding with no associated risks and to a nearly zero mortality rate. There are reports of UGB related to Sarcina ventriculi, gastric amyloidosis, jejunal lipoma, gastric schwannoma, hemobilia, esophageal varices, esophageal necrosis, aortoenteric fistula, homosuccus pancreaticus, and gastric trichbezoar in the literature. The common feature of these rare causes of UGB is that the diagnosis is difficult to establish before surgery. Fortunately, UGB with a clear lesion in the stomach itself is a clear sign for surgical intervention, and the diagnosis can only be verified by pathological examination with the help of immunohistochemical detection of a particular antigen for a specific condition. The clinical traits, diagnostic techniques, and the therapeutic, or surgical options of unusual causes of UGB reported in the literature are compiled in this review.