Ingestion of alendronate sodium (
Fosamax) had been reported to sometimes cause erosive or ulcerative esophagitis. Despite its widespread use and several case reports describing the clinical and endoscopic presentation, there has been limited discussion on the histologic appearances of the esophagitis caused by the medication. Here we describe one case of an elderly woman who presented with alendronate-induced esophagitis. The histopathologic changes that make this case unique are the large, \"bizarre\" squamous epithelial cells and scattered dyskaratotic cells, two findings not well described in previous reports. These unique features add to the histologic spectrum of alendronate-induced esophageal injury, and shall help differentiating this type of esophagitis from those with other etiologies.