Cutaneous leishmaniasis: Texas case diagnosed by electron microscopy

Abstract

A 78-year-old woman from south-central Texas without a history of travel outside the state presented with an erythematous papule on her right forearm. A biopsy specimen showed non-necrotizing granulomatous inflammation with negative stains for organisms. The lesion was recalcitrant to treatment with topical steroids, and a second biopsy specimen, obtained 3 months later, showed a histiocytic infiltrate in the upper dermis. Numerous, round, 1- to 30-microm bodies were seen within vacuoles in the histiocyte's cytoplasm. Giemsa, Grocott-Gomori methenamine-silver nitrate, and periodic acid-Schiff stains were negative. Electron microscopic examination of the paraffin-embedded tissue showed parasites diagnostic of leishmaniasis. On review of the literature, we found that 29 other cases of autochthonous cutaneous leishmaniasis have been reported in Texas. We emphasize the endemic nature of this condition in Texas.