Findings

The high power view (left image) shows the lamina propria of a villus with numerous pale-pink "foamy macrophages". These macrophages are loaded with many red staining (acid-fast) bacilli (right image).

Impression

MAI Infection

Pathology Pointer

Foamy macrophages are seen in a variety of conditions. Therefore, more specific diagnostic studies other than H&E staining are required to identify the causative agent. A positive acid-fast stain is strongly suggestive for myobacterial infection. However, further microbiological study is needed for the definitive diagnosis of Mycobacterium avium intracellulare.

Preparation

Fixed, H & E stain; AFB stain

View

Light micrograph

Specimen

Small intestine

Image Credit

Katsumi M. Miyai, M.D., Ph.D
Department of Pathology
School of Medicine
University of California, San Diego