Painful and swollen tongue: mucosal leishmaniasis due to Leishmania infantum

Leishmaniasis is a parasitic disease caused by different Leishmania species. L. infantum is found in the Mediterranean area. It usually causes visceral or cutaneous leishmaniasis, but rarely mucosal leishmaniasis (ML). A 62-year-old man with metastatic non-small-cell lung carcinoma visited the outpatient clinic because of a painful and swollen tongue. Initially, oral candidiasis was suspected and patient was unsuccessfully treated accordingly. Subsequently, a biopsy from the tongue was taken. Histology of the tongue biopsy showed an inflammation with histiocytes and Leishmania amastigotes. Molecular analysis determined these parasites as L. donovani complex. Based on the patient's travel history, ML caused by L. infantum was diagnosed. ML is an unusual presentation of L. infantum. ML is not only caused by Leishmania species endemic in Latin America, but also should be considered in the differential diagnosis for European patients. A biopsy of the affected location is needed to confirm the diagnosis.