Upper endoscopy revealed moderate to severe esophagitis in the middle esophagus (Fig. 1A). A high-dose proton-pump inhibitor was administered, and the patient continued receiving bevacizumab therapy. After three cycles, 1 month after initiation of bevacizumab, she presented with worsening chest pain and dysphagia. A second endoscopy revealed multiple deep ulcers in the middle esophagus with impending sign of perforation (Fig. 1B). Forceps biopsies were carefully performed; histologic findings showed superficial surface erosion which displays fibrinopurulent exudates and stroma which displays mixed inflammatory cells and increased vasculature. It was negative for cytomegalovirus and malignant cell (Fig. 2). Serum cytomegalovirus antibody was also negative. These results suggested bevacizumab-induced severe esophageal injury. Therefore, bevacizumab therapy was discontinued and proton pump inhibitor was maintained, resulting in gradual improvement in upper gastrointestinal symptoms. Informed consent was obtained from the patient.

Although bevacizumab is generally well tolerated, several serious adverse events including gastrointestinal perforation had been reported. Bevacizumab is an anti-vascular endothelial growth factor monoclonal antibody; thus, vascular injury and ischemia of the gastrointestinal tract is thought to contribute to these complications. When patients taking bevacizumab develop severe upper gastrointestinal symptoms, prompt endoscopic evaluation should be considered to enable early diagnosis and proper treatment.