Abstract
BACKGROUND AND AIMS: Gastrointestinal (GI) Mycobacterium avium complex (MAC) infection remains an under-recognized adverse event in severely immunocompromised patients. We present a case in which advanced upper GI endoscopy and high-resolution capsule endoscopy together provided unprecedented visualization of disease progression, forming the basis for a structured diagnostic review. METHODS: A 21-year-old woman with HIV (cluster of differentiation 4 count 8/μL) presented with chronic diarrhea, weight loss, and hypoalbuminemia. Upper endoscopy revealed severe duodenal villous atrophy and mucosal scalloping. Subsequent capsule endoscopy captured progressive mucosal changes extending into the distal jejunum and ileum, including pseudo-Whipple's disease nodularity. Diagnosis was confirmed by histology and polymerase chain reaction. A systematic review of 18 adult GI MAC cases with endoscopic documentation was performed to identify consistent visual patterns. RESULTS: Multimodal imaging revealed a continuum of pathology not previously captured in this detail. Literature synthesis showed that duodenojejunal nodularity, villous atrophy, and scalloping were the most common findings. On the basis of these patterns, we propose a 9-point MAC Suspicion Score to prompt early diagnostic consideration in high-risk patients. CONCLUSIONS: This case exemplifies how advanced endoscopic imaging can reveal subtle but diagnostic features of GI MAC and support a structured recognition strategy in severely immunocompromised hosts.