肛管直肠粘膜恶性黑色素瘤的临床与病理学分析

目的：探讨肛管直肠恶性黑色素瘤的临床发病特征和病理诊断特点。方法：采用免疫组织化学法和光镜法分析8例肛管直肠粘膜恶性黑色素瘤的临床表现、组织病理学变化特点及其与相关抗原表达的关系。结果：8例肛管直肠粘膜恶性黑色素瘤的发病均为老年患者，年龄最大79岁，最小59岁。临床均有便血，脓血便，或大便性状的改变。病理类型：息肉样型2例，肿瘤型2例，溃疡型4例；镜下肿瘤细胞表现为多样性，组织结构多样性，多数瘤细胞含有黑色素颗粒且色素含量分布不对称。免疫组化瘤细胞S-100、HMB-45、Malen-A呈不同程度的阳性表达。结论：肛管直肠粘膜恶性黑色素瘤肿瘤细胞和组织结构呈多样性，瘤细胞含有黑色素，S-100、HMB-45和Malen-A阳性有助于诊断和鉴别诊断。

Clinical and histopathologic analysis of mucosal melanomas in anal canal and rectum

Objective:To report 8 cases of mucosal melanomas in anal canal and rectum and to discuss the clinical and pathological features.Methods:The clinical characteristics and histopathological fetures of anorectal melanoma were discussed. Histopathoiogical fetures of 8 cases of anorectal melanoma were analyzed under light microscope,and also 4 cases using immunohistochemical staining.Results:The patients were all elder man,aged from 59 to 79 years old. Clinical characteristics were bloody stool, bloody purulent stool and alteration of bowel habit and bowel trait.The pathological patterns were polypoid,phymatoid and ulceractive. Histologically, the tumors were composed of variety of cell types and tissue patterns,and were melanin granule in the cell. Immunohistochemical staining showed the tumors were positive for S-100,HMB-45 and melan-A.Conclusion:Histopathological features of the anorectal melanoma were composed of variety of cell types and tissue patterns. Detection of S-100, HMB-45 and Melan-A protein may be helpful in the diagnosis of the tumor.