Clinical Presentation

A 52-year-old man presents with severe diarrhea.

(A) Small-bowel (SB) follow-through study shows diffusely thickened, irregular, nodular jejunal folds (between arrows). (B) Axial computed tomography (CT) after oral contrast shows a cluster of enlarged mesenteric lymph nodes in the midabdomen (arrows).

Differential Diagnosis

• Mycobacterium avium-intracellulare (MAI) infection: Irregular, nodular fold thickening, adenopathy, and diarrhea all point to MAI infection as the correct diagnosis.

• Whipple disease: Whipple disease can present with similar imaging and clinical findings, but with fatty, bulkier adenopathy.

• Lymphoma: Lymphoma can cause diffuse fold thickening, but typically the adenopathy will be more prominent.

Essential Facts