Case #4:

Clinical Presentation:
A 35 year old Hispanic man who is HIV+, presents with a 6 month history of a spreading, indurated, ulcerative skin lesion on the left arm (Case 4 Image 1). There is a satellite lesion. The patient recalls being bitten by a "fly" in Santo Domingo and subsequently developing a red papule at the bite site.

Clinical Diagnoses:
Staphylococcal skin abscess

Case 4 Image 2 and 3: Giemsa Stained smear of ulcer scrapings showing enormous numbers of intracellular, oval shaped bodies within macrophages. Extravisated red blood cells are present outside the macrophage.

Discussion:
Microbiologic Diagnosis:
Cutaneous Leishmaniasis
Caused by L tropica and L mexicana, which are transmitted by the bite of a Sandfly. Intracellular amastigotes of this protozoa may be differentiated from the yeasts of the fungus Histoplasma by the presence of a bar-like structure (Kinetoplast) adjacent to the nucleus (not seen in Image 2). In this patient, impaired cell-mediated immunity contributed to a chronic, spreading course of the lesion.