Case #481 – December, 2018

A 22-year-old male noticed painless, ulcerating lesions with crusting and mild swelling on his back and face. He had travelled to the rain forest of Peru five months earlier, where he experienced multiple insect bites all over his body. A biopsy specimen from a lesion on his back was sectioned and stained with hematoxylin and eosin (H&E) (Figure A). A smear of a scraping from the biopsy site was also made and stained with Giemsa stain (Figure B). Both figures show what was observed on the slides.

What is your diagnosis? Based on what criteria? What other testing would you recommend?

This case and images were kindly provided by the Pathology Department, Stony Brook University Hospital, Stony Brook, NY.

Figure A

Figure B

This was a case of cutaneous leishmaniasis caused by Leishmania species. The diagnosis was based on:

characteristic amastigotes in both figures. Amastigotes are small (1-2 mm x 1-5 mm), spherical to ovoid structures in which a nucleus and a kinetoplast are seen (blue arrows, Figures A and B).
presence of amastigotes within a macrophage (Figure B)
travel history to an endemic region and reported exposure to the insect vector (sand flies)

A species determination is essential for optimal treatment and also to differentiate amastigotes of Leishmania from those of Trypanosoma cruzi. This can be accomplished by molecular testing (PCR) performed on unpreserved material such as biopsy, aspirate, or bone marrow.

Figure A

Figure B

More on leishmaniasis: https://www.cdc.gov/dpdx/leishmaniasis/index.html

Images presented in the dpdx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.

DPDx is an educational resource designed for health professionals and laboratory scientists. For an overview including prevention, control, and treatment visit www.cdc.gov/parasites/.