Fig. 3
Disease-specific survival (DSS) in patients with anorectal melanoma stratified according to primary tumor histopathologic parameters. Each pair of images consists of a representative micrograph of a histopathologic feature of anorectal melanoma (left) and the respective Kaplan–Meier disease-specific survival estimates (right). a Tumor thickness, measured according to American Joint Commission on Cancer (AJCC) 8th edition cut-offs for cutaneous melanoma: T1 ≤ 1.0 mm, T2 > 1.0–2.0 mm, T3 > 2.0–4.0 mm, T4 > 4.0 mm (arrow- tumor thickness measured perpendicular to the surface along the thickest aspect of anorectal melanoma involving colonic mucosa; H&E, 20×). b Lymphovascular invasion (H&E, 400×). c Perineural invasion of nerve fibers (H&E, 400×). d Margin status, (−): negative, (+) IS: positive for in situ (IS), (+) Inv: positive for invasive melanoma; pictured: involvement of resection margin by invasive melanoma (H&E, 200×). e Histologic regression (H&E, 200×). f Tumor-associated ulceration, characterized by absence of epithelium overlying melanoma and associated fibrinous exudate on the mucosal surface (H&E, 200×). g Mitotic figures/mm2 (×4, arrows) within the invasive component (H&E, 400×). h Level of rectal wall invasion by melanoma, LP lamina propria, SM submucosa, MP muscularis propria and ≥S serosa and beyond; pictured: MP invasion (H&E, 20×). NI not identified, P present
