Fine-needle aspiration cytology in the diagnosis of cutaneous leishmaniasis

Abstract

Background: In areas of endemicity without sufficient laboratory infrastructure, cutaneous leishmaniasis (CL) is often diagnosed on the basis of clinical characteristics, but parasitologic confirmation is essential to exclude erroneous diagnoses. We compared fine-needle aspiration cytology (FNAC) with the conventional method of excisional biopsy to assess the efficacy, utility and accuracy of FNAC for the diagnosis of CL.

Materials and methods: In a consecutive series of 100 patients referred for a suspected CL lesion during June 2001 to May 2002, FNAC and 'excisional biopsy followed by histopathology' were done using hematoxylin and eosin (H&E) stain for both procedures.

Results: The study group included 40 males and 60 females, ranging in age from 1 to 70 with a mean age of 28.4 years. In more than 60% of cases, the lesions were on the face. By histopathological examination, 86 of 100 patients were positive for CL; while FNAC showed 77 cases as positive for CL. Taking histopathology as a standard diagnostic procedure, FNAC showed a remarkably high sensitivity (89%) and specificity (100%). The positive and negative predictive values were 100% and 60%, respectively.

Conclusion: FNAC is easier, less painful and more cost effective than the conventional 'scraping method/biopsy followed by histopathology'. The high sensitivity and specificity eliminate the need for other time consuming and invasive procedures. Limitations include poor sampling and poor yield.

Figure 1

Fine-needle aspiration smear showing 1) red blood cells, 2) lymphocytes, 3) neutrophils, 4) extracellular Leishman-Donovan bodies, 5) a macrophage filled with parasites in amastigote form (H&E stain).

Figure 2

Fine-needle aspiration smear of cutaneous leishmaniasis showing a single macrophage filled with many parasites and some extracellular parasites.

Figure 3

Histopathological section of cutaneous leishmaniasis lesion showing 1) macrophages filled with parasites, 2) some extracellular Leishman-Donovan bodies, and 3) plasma cells (H&E stain).