Ren Xiangxiang, Jin Xiaoshi, Xie Tianhao, Liu Litao, Wang Qiang, Sun Xingli, Zhang Meng
Department of General Surgery, Affiliated Hospital of Hebei University, Baoding, China.
Department of Dermatology, Affiliated Hospital of Hebei University, Baoding, China.
Front Med (Lausanne). 2025 Jul 2;12:1614614. doi: 10.3389/fmed.2025.1614614. eCollection 2025.
Primary Anorectal malignant melanoma (pARMM) is an exceedingly rare and aggressive malignancy, accounting for approximately 1% of anorectal cancers. It originates from melanocytes in the anorectal mucosa and lacks distinctive clinical features, leading to frequent misdiagnosis and advanced presentation.
A retrospective analysis was conducted on 9 patients (1 male, 8 females; median age 59 years) with histopathologically and immunohistochemically confirmed ARMM who underwent surgical resection (Wide Local Excision, WLE = 4; Abdominoperineal Resection, APR = 5) and had complete follow-up data (median 19 months, up to May 2025). Diagnostic methods included clinical evaluation, digital rectal exam (DRE), colonoscopy, imaging (CT), histopathology, and immunohistochemistry (IHC). Treatment approaches and outcomes were analyzed.
Common presenting symptoms were hematochezia (44.4%), tenesmus (22.2%), altered bowel habits, anal mass protrusion, or were asymptomatic (11.1% each). DRE revealed exophytic ( = 6) or polypoid ( = 3) masses. Colonoscopy showed lesions near the dentate line; only 33.3% had obvious pigmentation. IHC positivity: HMB-45/Melan-A 66.7%, S-100 55.6%. Pathological R0 resection was achieved in all patients. During follow-up, 3 patients (33.3%) developed distant metastases (lung, liver), 2 of whom died. Six patients remained disease-free.
Primary Anorectal malignant melanoma (pARMM) often presents with symptoms mimicking common benign anorectal conditions, leading to frequent diagnostic errors. Definitive diagnosis requires histopathological examination, with immunohistochemical markers (HMB-45 and Melan-A positivity) providing critical confirmation. While surgical resection remains the primary treatment, a growing expert consensus supports wide local excision with adequate margins (≥1 cm) as sufficient management. Emerging evidence indicates comparable survival outcomes to more radical procedures in appropriately selected patients.
原发性肛管恶性黑色素瘤（pARMM）是一种极其罕见且侵袭性强的恶性肿瘤，约占肛管癌的1%。它起源于肛管黏膜中的黑素细胞，缺乏独特的临床特征，导致频繁误诊和病情进展。
对9例经组织病理学和免疫组织化学确诊为ARMM的患者（1例男性，8例女性；中位年龄59岁）进行回顾性分析，这些患者接受了手术切除（局部广泛切除，WLE = 4例；腹会阴联合切除术，APR = 5例）且有完整的随访数据（中位随访19个月，截至2025年5月）。诊断方法包括临床评估、直肠指检（DRE）、结肠镜检查、影像学检查（CT）、组织病理学检查和免疫组织化学（IHC）检查。分析治疗方法和结果。
常见的临床表现为便血（44.4%）、里急后重（22.2%）、排便习惯改变、肛门肿物脱出或无症状（各占11.1%）。直肠指检发现外生性肿物（= 6例）或息肉样肿物（= 3例）。结肠镜检查显示病变位于齿状线附近；只有33.3%有明显色素沉着。免疫组织化学阳性率：HMB - 45/Melan - A为66.7%，S - 100为55.6%。所有患者均实现了病理R0切除。随访期间，3例患者（33.3%）发生远处转移（肺、肝），其中2例死亡。6例患者无疾病复发。
原发性肛管恶性黑色素瘤（pARMM）常表现出类似常见良性肛管疾病的症状，导致频繁的诊断错误。明确诊断需要组织病理学检查，免疫组织化学标志物（HMB - 45和Melan - A阳性）提供关键确诊依据。虽然手术切除仍是主要治疗方法，但越来越多的专家共识支持采用足够切缘（≥1 cm）的局部广泛切除作为充分的治疗手段。新出现的证据表明，在适当选择的患者中，其生存结果与更激进的手术相当。
