Primary intramedullary melanocytoma presenting with lower limbs, defecation, and erectile dysfunction: A case report and review of the literature

Figure 2 Postoperative pathology images showing the typical features of melanocytoma. A: Hematoxylin and eosin (HE) staining (400 ×) revealed spindle and epithelioid cells containing melanin pigment in the cytoplasm assembled to form sheets, bundles, nests, or whorls surrounded by reticulin fibres (yellow arrow); B: HE staining (400 ×) after removing melanin pigment in the cytoplasm; C-H: Immunohistochemical staining (400 ×) demonstrated human melanoma black 45 (C), antimelanoma antibody (D), and sex determinant region Y box 10 protein (E) were positive. Besides, epithelial membrane antigen (F) and glial fibrillary acidic protein (G) were negative, and the proliferative index was only 3% (H).