Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea.
Int J Mol Sci. 2024 Sep 27;25(19):10414. doi: 10.3390/ijms251910414.
Acral melanoma (AM) is a subtype of cutaneous melanoma located on the palms, soles, and nails. The pathogenesis of AM involves mechanical stimulation and characteristic tumor-promoting mutations, such as those in the proto-oncogene. Dermoscopy is useful for diagnosing AM, which is characterized by parallel ridge patterns and irregular diffuse pigmentation. Although histopathological confirmation is the gold standard for diagnosing AM, lesions showing minimal histopathological changes should be considered early-stage AM if they clinically resemble it. Recently, immunohistochemical staining of preferentially expressed antigen in melanoma has been recognized as a useful method to distinguish benign from malignant melanocytic tumors. Research reveals that AM is associated with an immunosuppressive microenvironment characterized by increased numbers of M2 macrophages and regulatory T cells, alongside a decreased number of tumor-infiltrating lymphocytes. Mohs micrographic surgery or digit-sparing wide local excision has been explored to improve quality of life and replace wide local excision or proximal amputation. AM has a worse prognosis than other subtypes, even in the early stages, indicating its inherent aggressiveness.
肢端黑色素瘤（AM）是一种位于手掌、足底和指甲的皮肤黑色素瘤亚型。AM 的发病机制涉及机械刺激和特征性的肿瘤促进突变，如原癌基因中的突变。皮肤镜检查有助于诊断 AM，其特征是平行脊状模式和不规则弥漫性色素沉着。虽然组织病理学确认为诊断 AM 的金标准，但如果临床上类似 AM 且病变显示最小的组织病理学改变，则应考虑为早期 AM。最近，黑色素瘤中优先表达抗原的免疫组织化学染色已被认为是区分良性和恶性黑色素瘤肿瘤的有用方法。研究表明，AM 与免疫抑制微环境相关，其特征是 M2 巨噬细胞和调节性 T 细胞数量增加，同时肿瘤浸润淋巴细胞数量减少。已经探索了 Mohs 显微外科或保留指的广泛局部切除术，以提高生活质量并替代广泛局部切除术或近端截肢。即使在早期阶段，AM 的预后也比其他亚型差，这表明其固有的侵袭性。
