A 25-year-old immunocompetent male was referred to our dermatology service with a history of 4-cm-long chronic firm mass of the dorsal metatarsal right foot. He recalled having suffered a trauma on this foot in the Central African Republic 1 year ago. The lesion showed no abscesses or fistulae, and there was no osteomyelitis (as confirmed by radiography). The hematological and biochemical laboratory test results were unremarkable. A surgical biopsy was performed, and black, regular grains a few millimeters long were collected and sent with the tissue biopsy specimens for histopathology and bacterial and fungal culture. Figure 1A, B, and C demonstrate the organism with hematoxylin and eosin (H&E) and Grocott silver stains.
FIG 1.
(A) Mixed inflammatory infiltrate and progressive fibrosis surrounding black grains (H&E stain; magnification, ×25). (B and C) Structures (2 to 4 μm) in a black grain (H&E stain at ×200 [B] and Grocott silver stain at ×1,000 [C]).
For answer and discussion, see page 2292 in this issue (https://doi.org/10.1128/JCM.02484-15).