Unsuspected Visceral Leishmaniasis Infiltrating a Squamous Cell Carcinoma

Amastigotes of the genus Leishmania have been observed in biopsies of apparently unrelated lesions in patients with AIDS and visceral leishmaniasis. We describe the case of a 40-year-old man with human immunodeficiency virus infection and severe immunodepression in whom the presence of the parasite was detected as an incidental finding on histological study of a perianal squamous cell carcinoma. This finding led to the diagnosis and subsequent treatment of previously unsuspected visceral leishmaniasis. In a review of the literature we have found