肛管直肠恶性黑色素瘤的临床病理特点并文献复习

目的:探讨肛管直肠恶性黑色素瘤的临床病理特征、免疫表型、诊断及鉴别诊断。方法:对5例肛管直肠恶性黑色素瘤病例的组织形态、免疫组化等进行观察，并复习相关文献。结果:5例患者男性2例，女性3例，年龄60~84岁，平均70.2岁，临床主要为直肠出血、直肠肿块和疼痛等表现，镜下以上皮样和梭形细胞为主要成分，瘤细胞呈巢团或片状分布伴有多形性，细胞核大而深染，胞浆丰富，细胞有丝分裂指数高，并可见不典型性核分裂象，部分肿瘤细胞内见有黑色素沉着。免疫组化显示肿瘤细胞可表达S-100、HMB-45和Melan A，不表达AE1/AE3。结论:肛管直肠恶性黑色素瘤是一种少见、具有侵袭性的肿瘤，因其解剖学部位和非特异性临床表现，诊断较困难，确诊有赖于常规病理和免疫组化，临床医师应当高度重视该病，避免延误治疗。

Anorectal malignant melanoma:A clinicopathological observation and literature review

Objective:To explore the clinicopathological characteristics,immune profile,diagnosis and differential diagnosis of anorectal malignant melanoma(ARMM).Methods:Five cases of anorectal malignant melanoma were studied with histopathological and immunohistochemical staining.Their clinical and pathological findings were analyzed along with a review of similar studies in the literature.Results:We have selected 5 cases of anorectal malignant melanoma in our department for the study,2 males and 3 females,with ages ranging from 60 to 84 and an averaged age of 70.2 years old.The study showed that rectal bleeding,rectal mass and pain were the primary clinical symptoms.Under microscopy,the tumor cells were epithelioid and spindle,and arranged in nests or sheets.The tumor was composed of pleomorphic cells with large hyperchromatic nuclei and large cytoplasm.A higher mitotic index and atypical mitoses were observed.Cells with pigmentation was also observed in the tumor.Immunohistochemically,the tumor cells showed positive reactivity to S-100,HMB-45 and Melan A,and negative reactivity to AE1/AE3.Conclusion:Anorectal malignant melanoma is rare but aggressive tumor.ARMM can be very difficult to diagnose because of its lack of specific clinic symptoms and anatomic location.Confirmation of this disease diagnosis heavily depends on morphological observation of pathology and immunohistochemistry.Therefore,a high degree of clinical suspicion is required to avoid delays in treatment.