Cytomegalovirus esophagitis in AIDS: diagnosis by endoscopic biopsy.

We have reviewed 28 esophageal biopsies from 28 patients with the acquired immune deficiency syndrome (AIDS), over a 1-yr period. Indications for esophageal biopsy were dysphagia persisting after antifungal therapy and/or radiologic evidence of esophageal ulcer. We compared the frequency of detecting cytomegalovirus (CMV) infection on hematoxylin and eosin (H&E) stain with immunoperoxidase staining for CMV antigens. Five biopsies were positive for CMV by H&E stain and immunoperoxidase. Infected cells could often be identified in the granulation tissue and, in one severe case, in stromal papillae of the intact mucosa. Squamous cells were never positive. Thirteen biopsies consisted only of squamous epithelium, and all of these were negative by both techniques. Among the remaining 10 cases, no CMV inclusions were identified by H&E. Three of these biopsies displayed staining for viral antigens. In all cases positive by immunoperoxidase, numerous cells positive for viral antigens did not display any of the CMV-specific morphologic diagnostic criteria. Other coexisting diagnoses included candidiasis, Kaposi's sarcoma, and malignant lymphoma. We conclude 1) CMV infection of the esophagus is common in AIDS patients with esophageal ulcer or esophagitis resistant to antifungal therapy; 2) multiple infections or neoplasms may coexist; 3) since CMV apparently does not infect squamous epithelium and only rarely endothelium in stromal papillae, deep biopsies are necessary for diagnosis; and 4) immunoperoxidase staining is required for maximum diagnostic yield.