Residual anorectal malignant melanoma presenting as polyp-like lesion detected during colonoscopic withdrawal observation: A case report and review of literature

Figure 1 Colonoscopy findings. A: Slightly coarse mucosa at the prior anal canal surgical scar; B: Additional view of slightly coarse mucosa at the prior anal canal surgical scar (arrow); C: Narrow-band imaging showing features consistent with National Institute for Health and Care Excellence (NICE) type 1 classification (arrow); D: Additional view of features consistent with NICE type 1 classification.

Figure 2 Immunohistochemical findings of the biopsy specimen. A: Hematoxylin and eosin staining (× 200); B: Immunohistochemical staining for human melanoma black-45 (× 200); C: Immunohistochemical staining for microphthalmia-associated transcription factor (× 200); D: Immunohistochemical staining for CD63 (× 200).