THE ENDOSCOPIC APPEARANCE OF SEVERE INTESTINAL MYCOBACTERIUM-AVIUM COMPLEX INFECTION AS A COARSELY GRANULAR MUCOSA DUE TO MASSIVE INFILTRATION AND EXPANSION OF INTESTINAL VILLI WITHOUT MUCOSAL EXUDATION

Although Mycobacterium avium complex (MAC) is the most common opportunistic pathogen at postmortem in patients with AIDS, many cases are not recognized premortem. A patient with advanced AIDS had diarrhea, fecal occult blood, and iron deficiency anemia. Esophagogastroduodenoscopy showed an extensive coarsely granular mucosa, resistant to endoscopic irrigation and brushing, in the descending duodenum. Histologic analysis of duodenal biopsies confirmed expansion of intestinal villi due to massive villar infiltration by acid-fast bacilli and no mucosal exudation. An absence of mucosal exudation is consistent with an attenuated local immunologic response in advanced AIDS. MAC was isolated from mycobacterial culture of duodenal biopsies. The currently reported endoscopic appearance of intestinal MAC can aid in diagnosis by alerting the endoscopist to send biopsies for mycobacterial stains and cultures when MAC infection is suggested by this endoscopic appearance. However, even in the absence of endoscopically evident lesions, gastrointestinal endoscopic biopsy is appropriate to exclude occult opportunistic pathogens in an AIDS patient with wasting or significant gastrointestinal complaints, The currently reported pathologic findings show that villar engorgement and hypertrophy is a sufficient explanation for the granular endoscopic appearance of intestinal MAC and that mucosal exudation is not required to produce this appearance.