Cytomorphological Variations of Leishman-Donovan Bodies Found in Cutaneous Leishmaniasis Patients in Sri Lanka

Leishmania parasites undergo a dimorphic life cycle. Diagnosis of cutaneous leishmaniasis (CL) is primarily made by the microscopic identification of the amastigote form of the parasite in a smear. Therefore, correct identification of Leishman-Donovan (LD) bodies in smears is crucial for CL confirmation. The aim of this study was to provide a broad overview of different cytomorphologies of LD bodies to improve the sensitivity of microscopic detection of Leishmania donovani, which causes CL in Sri Lanka. A total of 125 smears, prepared from patients who met the positive diagnostic criteria of CL, were Giemsa stained and examined microscopically. The density, cellular location and all possible cytomorphological forms of the parasite were documented. A total of 10 different cytomorphological forms of LD bodies were identified. Among them, the round form was observed only intracellularly. The other morphological forms, namely the pear shape, cigarette shape, candle flame form, embryo shape, flagellate form, binary form and rosette form, were found only extracellularly. The spindle form and lens shape were observed in both intracellular and extracellular locations. L. donovani amastigotes have a wide range of morphologies besides their classical forms. Although Leishmania are considered as obligatory intracellular parasites, they manage to survive successfully within the extracellular hostile conditions as well. Therefore, having a broader view of different morphological forms for Leishmania parasites may help to improve diagnosis of CL.