Histological investigations of melanised focal changes. (A) Transverse section of necrotic muscle cells (asterisk) and severe fibrosis (arrow) with infiltrates of leukocytes. A cell-rich granuloma with melanin-containing cells is present in the right part of the picture (G), displaying a heterogeneous morphology (HE staining). (B) Severe vacuolisation and adipocytes with surrounding melano-macrophages (black) and clusters of regenerating myocytes with a basophilc cytoplasm (arrow) (HE staining). (C) Multiple vacuoles in an area with severe fibrosis (intense red staining) (van Gieson staining). (D) Several iron-containing macrophage-like cells (blue staining) in association with melano-macrophages (black) (Pearls’ Berlin blue staining). (A, C) scale bar = 100 μm, (B, D) scale bar = 50 μm.