Fig. 1

Representative panel of dermatofibroma originating in a leprosy lesion: a, c, e, and g Hematoxylin-eosin-stained histological section showing the dermatofibroma in the center (light arrows) and the leprosy lesion in regression at the periphery (dark arrows); b, d, f, and h histological section for bacilloscopy (Fite-Faraco) showing absence of bacilli in the dermatofibroma (clear arrows) and presence of fragmented bacilli in the leprosy lesion in peripheral regression (dark arrows); i, j, k, l basic immunohistochemical panel – expression of anti-CD68 (i) in leprosy lesion macrophages and the absence of anti-factor XIIIa expression in the same macrophages (j); the absence of anti-CD68 expression (k) and the expression of anti-factor XIIIa in dermatofibroma cells