Fig. 2

Surgically excised mass surface with skin and incomplete capsule, most of which were black (a). The section observed was solid and black, with necrosis present in certain parts (b). HE staining showed the distribution of tumor cells in the dermis in sheets or nests (magnification × 100) (c). HE staining showed round or oval tumor cell nuclei, with evident nucleoli and nuclear divisions were common. A large amount of melanin was seen in the cytoplasm, and local epithelium was absent (magnification × 400) (d). IHC showed Melan-A positive (magnification × 200) (e). IHC showed Tyrosinase positive (magnification ×400) (f)