Primary laryngeal leishmaniasis: an unusual diagnosis at an unusual site

Introduction

Leishmaniasis is a zoonotic vector-borne disease caused by protozoa of the genus Leishmania and usually transmitted by the bite of the female Phlebotomus or Lutzomyia sandfly. ¹ Leishmaniasis, although common in the northern and north-east belt of India, is not very common in the south. Only few cases of laryngeal involvement have been reported worldwide.^2–5 We report the case of a 75-year-old man who presented with complaints of hoarseness of voice and discomfort. He had no other systemic complaints and was immunocompetent. On undertaking a biopsy, leishmaniasis was diagnosed. This case is reported for its rarity and unique presentation.

Case report

A 75-year-old man presented to our ENT department with complaints of hoarseness of voice and discomfort for six months. He had no other complaints. He lived in south India and had not travelled to the northern part of the country. No skin lesions were noted on physical examination; there was no hepatosplenomegaly/lymphadenopathy. Indirect laryngoscopy revealed a pinkish-white, friable nodule on the vocal cord, which led to clinical suspicion of squamous carcinoma of the larynx. Direct laryngoscopy was performed and a biopsy was taken for histopathological examination. The laboratory tests were unremarkable. On histopathological examination, numerous extracellular LD bodies were seen in an inflammatory milieu comprising lymphocytes, plasma cells and macrophages set in an oedematous sub-epithelial stroma. Giemsa stain revealed the presence of amastigote forms within histiocytes (Figure 1). OPEN IN VIEWER

A polymerase chain reaction (PCR) test was done and a generic diagnosis of infection by Leishmania spp. was made. The patient was treated with liposomal amphotericin B (3 mg/kg/per day for seven days and, subsequently, 3 mg/kg once a week for five weeks). At the end of treatment, symptoms resolved and did not recur.

Discussion

In a tropical country such as India, vector-borne diseases are common but leishmaniasis is not common in the southern parts. Mucocutaneous or mucosal leishmaniasis is much less commonly reported; it occurs in 1–10% of patients who have had previous episodes of cutaneous leishmaniasis. ⁵ This case is presented for its unique presentation, with no other related lesions elsewhere in the body. Immunodeficiency, history of travel to endemic areas, use of immunosuppressive drugs and smoking are the known risk factors for laryngeal leishmaniasis.^2,5 In our case, the patient did not have any of these risk factors. On clinical examination alone, it can mimic a malignant lesion. Hence, a multidisciplinary approach is often needed to confirm the diagnosis of leishmaniasis. In this case, endoscopy, histopathological examination and PCR were done to make a firm diagnosis. Giemsa staining was able to reveal the amastigotes as fine, intra- and extra-histiocytic granules. Microscopic examination is the most widely used and the cheapest technique; however, the amastigotes are usually scarce and definitive diagnosis at species level can be done only by molecular methods. The multidisciplinary approach used in this case helped in the early diagnosis of the disease and subsequent treatment of the condition with resolution of symptoms. Leishmaniasis, as was earlier presumed, is not restricted to endemic areas alone and this case emphasises the need to consider leishmaniasis as a differential when histopathological examination reveals prominent lymphoplasmacytic infiltrate and macrophages.

Antimony-containing compounds are the main drugs used to treat leishmaniasis (Meglumine antimoniate and Sodium stibogluconate). ⁶ Other drugs that may be used include Amphotericin B, Ketoconazole, Miltefosine, Paromomycin and Pentamidine. ⁷ Large, randomised trials are needed to define the most effective therapeutic protocol, owing to resistance patterns and the expected rise of the incidence of leishmaniasis in the near future, as a result of significant environmental and anthroponotic changes.