Aspects of the association between leishmaniasis and malignant disorders

Given the prevalence of leishmaniasis and cancer, the co-existence of these two diseases may be merely coincidental. However, a number of epidemiological, experimental and laboratory studies suggest that an association between these two entities does exist. The aim of this review is to summarise the occurrence of leishmaniasis as an opportunistic infection associated with malignant disorders and to present the available literature potentially linking this infection with the development of cancerous lesions. We searched electronic databases and evaluated 37 studies involving 44 patients. Four different types of association between leishmaniasis and cancer were established: leishmaniasis mimicking a malignant disorder, such as lymphoma; leishmaniasis arising as a difficult to diagnose and treat infection among patients receiving chemotherapy for various malignant disorders; simultaneous diagnosis of leishmaniasis and a neoplastic disorder in the same tissue samples of immunocompromised patients; and direct involvement of Leishmania spp. in the pathogenesis/occurrence of malignant lesions, especially of the skin and mucous membranes. The main conclusion of this review is that leishmaniasis can directly or indirectly affect the presentation, diagnosis and course of various malignant disorders and it should be considered in the differential diagnosis of malignancies in geographic areas where it is endemic and/or in patients with travel history to these areas.