Case #399 – July 2015

A skin biopsy specimen was collected from the clavicle region of a 45-year-old male who presented with what appeared to be a pigmented lesion. The patient resides in Kentucky and has no known international travel. The biopsy specimen was sent to Pathology for routine histologic work-up. Objects suggestive of an organism were examined on slides stained with hematoxylin-and-eosin (H&E). The attending pathologist captured images and sent them to CDC-DPDx for diagnostic assistance. Figures A–E represent five of the images received. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

Figure E

The organism depicted in the images was a hard tick (Acari: Ixodidae). Unfortunately, further identification was not possible after specimen processing and subsequent sectioning. In the images, the thick tegument and striated musculature characteristic of arthropods can be observed. In Figure A (arrows) cross-sections of legs can be observed.

Figure A