原位恶性黑素瘤临床病理分析及鉴别诊断

Clinical and histopathological features of malignant melanoma in situ:report of 3 cases and literature review

关键词:  恶性黑素痼  原位  诊断  免疫组化  预后

Key words:  malignant melanoma  in situ  diagnosis  immunohistochemistry  prognosis

摘要:

目的探讨原位恶性黑素瘤（malignant melanoma in situ, MMS)的临床和病理组织学特点以及鉴别诊断。方法对3例原位黑素瘤进行临床表现、病理形态学及免疫组化检查分析，随访并复习相关文献。3例MMS均为女性，平均年龄56.7岁（53~61岁），病程0.5~2年。甲下2例，外阴1例。结果临床检查病灶表现为大于7mm形状不规则的色素斑,边界不清,深浅不一。病理组织学观察,见单个异型黑素细胞在表皮内的不均匀增生，部分细胞分布于表皮的中上层，可见不规则的巢状细胞团。瘤细胞核大、深染，可见核分裂,胞浆树突状，含有较粗 大的色素颗粒;免疫组化S-100,HMB-45,Melan-A阳性。随访32~35个月，2例稳定,外阴MMS 2年后原位复发。结论MMS需与交界痣、非典型性黑色素细胞痣及皮肢Paget病等鉴别，早期诊断需结合临床和病理形态特点以及免疫组织化学染色法。

Abstract:

Objective To investigate the clinicalpathologic characteristics of malignant melanoma in situ(MMS) and its differential diagnosis. Methods Three cases of malignant melanoma in situ (MMS) were reported and related literatures were reviewed. All 3 patients of MMS were females with an average age of 56.7 years(53-61 years).The duration of symptoms or signs ranged from 0.5 to 2 years. Two cases were subungual melanoma in situ and another one was vulvar melanoma.Results The lesions were >0.7cm in diameter and presented as ill-defined, variably dark pigmented. Microscopically, single-melanocytic proliferation was identified along the dermo-epidermal junction and some was located in the middle and upper layer of the epidermis. Some tumor cells formed noncohesive nests with different sizes and shapes. The cells had enlarged hyperchromatic nucleui, long dendritic cytoplasm and dusty cytoplasmic melanin and were positive for HMB45，Melan-A and S-100 by immunohistochemistry. Occasional mitotic figures were present. During the follow-up of 32~35 months, two cases of subungual MMS were stable, and one case with vulval MMS recurred two years later. Conclusion MMS should be distinguished from junctional nevus，dysplastic melanocytic naevi and cutaneous Paget’s disease. The early diagnosis of MMS is based on the clinicopathologic features in combination with immunohistochemical staining.