肛管直肠恶性黑色素瘤临床病理误诊分析

目的分析肛管直肠恶性黑色素瘤临床及病理误诊的原因 ,探讨避免误诊的办法 .方法对 15例肛管直肠恶性黑色素瘤进行回顾性分析和免疫组化观察 .结果临床误诊率为 86 7% (13/15).其中误诊为良性病变占 66 7% (10/15),误诊为痔或痔伴有肛周脓肿 7例、息肉 2例及慢性炎症 1例； 3例误诊为肛管直肠癌 .延误诊治时间 3个月至 1年 .活检病理误诊率为 53 3% (8/15),其中误诊为低分化腺癌 6例 ,平滑肌肉瘤、类癌各 1例 . 5例无色素性恶性黑色素瘤全部误诊 .结论肛管直肠恶性黑色素瘤临床误诊率高 ,病理活检难以准确分型 .临床和病理医生应密切配合 ,作直肠指诊 ,及时活检；对病理标本多作切片 ,仔细寻找黑色素颗粒并对可疑标本进行免疫组织化学检查 ,有助明确诊断 .

Clinicopathological analysis for misdiagnosis of anorectal malignant melanoma

Objective To analyze the causes of clinical and pathological misdiagnosis of anorectal malignant melanoma and investigate how to avoid such misdiagnosis.Methods Clinical and pathological data,including immunohistochemical staining of 15 cases with anorectal malignant melanoma were analyzed retrospectively.Results Clinical misdiagnosis rate was 86 7% (13/15), of which 5 cases were misdiagnosed as anorectal cancers and 10 cases as benign diseases,including 7 as hemorrhoids accompanied by anal abscess or not,2 as polypus,one as chronic inflammation.The correct diagnosis and therapy were delayed from three months to one year.Misdiagnosis rate of pathological biopsy was 53 3% (8/15)including 6 cases misdiagnosed as poor differentiated adenocarcinoma,one as leiomyosarcoma and 1 as carcinoid.All 5 cases of malignant amelanotic melanoma were misdiagnosed.Conclusions Because of high clinical misdiagnosis rate and difficulty to make diagnosis of histological type by pathological biopsy,it is important for clinical surgeons and pathological experts to cooperate closely,and to perform digital examination and biopsy in time.It is helpful to make a correct diagnosis that more slides and melanotic pigment granules should be examined carefully,and suspected samples should receive immunohistochemical assay.