A diffuse foamy histiocytic infiltrate involves the lamina propria of the duodenum. There is no acute inflammatory or other reaction observed.

Silver stain highlights the small, ovoid nature of the Histoplasma organisms.

The foamy macrophages clearly contain numerous tiny intracytoplasmic organisms.

Histoplasma capsulatum is a fungus responsible for the development of a subclinical infection that affects many individuals residing inthe southeastern and midwestern United States. The infectious agent is an airborne spore, which when inhaled, may cause a flulike illness

with mild pulmonary symptoms. In most individuals, the condition is self limited, but it can cause become disseminated and affect the GI tract in immunocompromised patients such as those with HIV.

Any level of the colon may be involved. Typical findings include ulcers, nodules, or obstructive mass lesions.

The antifungal medication Amphotericin.

A significant proportion of those with AIDS experience a relapse and require maintainance therapy with itraconazole.

• Heart : Histoplasma Endocarditis

• Small Intestines : MAI Infection

• Small Intestines : Eosinophilic Enteritis due to Nematode Infection

• Small Intestines : Giardiasis

• Lung : Coccidioidomycosis