Mucosal leishmaniasis of the nasal septum: diagnostic pitfalls and management considerations

Leishmaniasis is a chronic parasitic disease caused by a protozoan of the order Kinetoplastida, transmitted through the bite of infected sandflies. Its mucosal form with sinonasal involvement is exceptional but clinically relevant, potentially causing granulomatous lesions, nasal obstruction, and epistaxis, mimicking inflammatory or malignant disease. In the Old World (Europe, Asia, Africa), it is usually associated with Leishmania infantum, whereas in the New World (America) L. braziliensis predominates, generally following a previous or concomitant cutaneous lesion. Early diagnosis and treatment are crucial due to the risk of local and systemic progression. The aim of this study is to highlight the diagnostic pitfalls and management considerations of mucosal leishmaniasis confined to the nasal septum in a European clinical setting by presenting a case series.

Three cases diagnosed between 2018 and 2023 were retrospectively reviewed. All were male patients (aged 37, 43, and 76 years) with mucosal leishmaniasis involving exclusively the nasal septum, without previous or concomitant cutaneous lesions and no history of travel to endemic areas. Diagnosis was confirmed by lesion biopsy and Giemsa staining, demonstrating the presence of intracellular amastigotes. All patients received treatment with liposomal amphotericin B.

All three patients achieved complete clinical resolution. Reversible adverse effects were documented: two cases of acute renal failure and one case of sinus bradycardia, successfully managed with temporary treatment suspension and intensive hydration. Patient number 2, immunosuppressed due to Crohn's disease, experienced recurrence several years later, initially treated with fluconazole and, due to persistent lesions, with a second course of liposomal amphotericin B.

Isolated septal mucosal leishmaniasis is a rare and potentially underdiagnosed entity, particularly in the absence of cutaneous lesions, requiring a high index of clinical suspicion and histopathological confirmation. Liposomal amphotericin B is effective and safe under close monitoring. Immunosuppression may increase the risk of recurrence, justifying prolonged follow-up and multidisciplinary management.