Answer to July 2016 Photo Quiz

Answer: Anal leishmaniasis. Giemsa-stained touch preparations of the anal biopsy material showed intracellular Leishmania amastigotes. The patient's serologic analysis result for Leishmania was positive. Colonic histology showed no Leishmania, and a bone marrow biopsy showed no significant findings. Results for both culture and direct microscopic examination of bone marrow aspirate were negative for Leishmania. The patient was treated with 3 mg/kg of body weight of liposomal amphotericin B on days 1 to 5 daily and then on days 14 and 21 (with a total dose of 21 mg/kg). The patient had a partial clinical response to treatment, with disappearance of local symptoms but with hardly any reduction of the size of the lesion. Therefore, a surgical excision of the lesion was performed 3 months later. The staining and culture of the subsequent tissue sample showed no Leishmania.

Leishmaniasis is a zoonotic disease, endemic in some Mediterranean countries, such as Spain (1). Leishmania is a facultative intracellular protozoan. The parasite infects the macrophages of its mammalian hosts, and hosts who are immunocompetent recover after development of effective cell-mediated immunity, which allows the activation of macrophages to a microbicidal state. A decrease in CD4⁺ cell count and reduced production of interferon, such as in HIV-positive patients, may facilitate the spread of Leishmania protozoa and diffuse visceral parasitization, thus resulting in unusual locations of these organisms (1).

Atypical locations, such as with visceral leishmaniasis (VL) confined to the gastrointestinal tract alone, can occur, especially in HIV-positive patients (2); however, this condition is highly unusual in immunocompetent individuals (3). In patients with gastrointestinal leishmaniasis, the duodenal mucosa has been described as the region of the digestive tract most frequently affected (90% of cases) (4). Absence of hepatosplenomegaly is exceptional in VL (5, 6). Although rare, there have been reported cases of intestinal leishmaniasis without pancytopenia (7). However, there have been only a few reported cases of leishmaniasis with anal involvement, all of them in HIV-positive patients except for one case (8–11).

We believe that a relative cellular immunosuppression unrelated to HIV in our case produced this atypical form of leishmaniasis with anal involvement without bone marrow infiltration or hepatosplenomegaly and without other sites of the gastrointestinal tract affected. In atypical cases, such as this one, distinguishing between the cutaneous and visceral forms of the disease can be difficult. However, systemic manifestations such as weight loss, mucocutaneous involvement in places not exposed to sandfly bite, and a positive serologic analysis result for Leishmania, as well as hypergammaglobulinemia, high erythrocyte sedimentation rate, circulating immune complexes like anti-smooth muscle antibody (12), and positive rheumatoid factor (13), strongly suggest that this case fits with a VL form.

In conclusion, in areas of endemicity, leishmaniasis should be considered possible in elderly patients with decreased CD4⁺ cell counts and an anal mass without evidence of tumor cells in the biopsy specimen.

(See page 1675 in this issue [doi:10.1128/JCM.01529-14] for photo quiz case presentation.)