case_images: PMC11143801_01
case_images: (a) Clinical photo of right distal hallux prior to partial amputation. (b) H&E stain of ulcerated nail bed, 2x magnification. (c) MelanA stain of nail bed, 10x magnification. (d) H&E stain demonstrating perineural invasion of melanoma, 10x magnification. (e) H&E stain demonstrating melanoma invasion into periosteum and focally into a marrow space 2x magnification. (f) MelanA stain of inguinal lymph node demonstrating metastasis, 4x magnification.
case_images: 10.1177_2050313X241257698-fig1.jpg
case_images: PMC11143801_01_10.1177_2050313X241257698-fig1.jpg
case_images: fig1-2050313X241257698
case_images: On exam, the ulcer was full thickness with a friable base, irregular edges, and black discoloration at left edge of the nail matrix (Figure 1(a)). A tissue biopsy from the ulcer margin was obtained and revealed melanoma with ulceration (Figure 1(b)):the tumor was positive for Melan-A (Figure 1(c)), S100, and Sox10, and negative pancytokeratin AE1/AE3 immunohistochemical stains. The hallux amputation revealed melanoma with Breslow thickness 13 mm, Clark level >= V, with extension to deep dorsal soft tissue, perineural invasion (Figure 1(d)), and focal invasion of underlying bone (Figure 1(e)). The extent of ulceration was up to 8 mm in width, with a mitotic rate of 20 mitoses per mm2. Immunohistochemical stain Melan-A was positive in one right inguinal lymph node, supporting lymph node involvement by melanoma (Figure 1(f)).