中枢神经黑色素细胞瘤的临床病理特征及MRI分析

目的：复习文献，探讨中枢神经系统黑色素细胞瘤（melanocytoma，MC）的MRI及病理学特点、诊断与鉴别诊断及预后。方法：回顾性分析2009－2014年收治的4例中枢神经黑色素细胞瘤患者的病史、MRI特点／病理诊断及免疫组化结果。结果：4例患者中男性3例，女性1例，年龄41～64岁，平均53岁。4例患者中，3例随访6～36个月，均健在，另外1例失访。MRI表现为稍短T1WI信号，T2WI短信号。大体观察肿瘤均为单发，呈结节状生长。组织学上肿瘤细胞呈束状排列，梭形或上皮样，核圆形或卵圆形，异型不明显，核分裂象罕见，少数伴有出血坏死或局部浸润。免疫组化示瘤细胞HMB45（＋）、S－100（＋）、MART－1（melan－A）、Vimentin（＋）、CK（＋）、Ki－67（约2％～10％＋）、EMA（－）、PR（－）、GFAP（－）、Syn（－）、NSE（－）、NF（－）及A103（－）。结论：MC较为少见，在MRI上需要与神经鞘瘤、脊膜瘤、脂肪瘤及血管瘤等鉴别。MC通常在MRI T1WI上与灰质信号相等或稍高，而在T2WI上呈低信号，其他肿瘤则各有其不同特点。MC多为交界性或低度恶性，倾向局部复发，主要的治疗方法是手术切除病灶。容易与恶性黑色素瘤以及伴有黑色素细胞分化的其他肿瘤混淆，诊断依赖于影像学、病理组织学、免疫组化观察。

Clinicopathology and iconography study of the melanocytoma in central nervous system

Objective:To explore the pathology and MRI features,histogenesis,diagnosis and differential diagno-sis,therapy and prognosis of the melanocytoma in central nervous system(CNS).Methods:To retrospective analyze the medical history,MRI features,histogenesis diagnosis and immunohistochemical results of 4 cases of melanocytoma in 2009-2014 year.Results:3 patients were male and 1 was female,aged 41 ~64 years(mean 53 years).3 cases were followed-up for 6 ~36 months,and no one was dead,1 case reoccured.The characteristic feature of MRI is short signal on T1WI,short signal on T2WI.Tumors were nodular,all of which were single.Histologically,the tumor consisted of spindle cells and epithelioicl cells arranged in bunchiness.The nuclei were oval and had no obvious atyp-ia and mitosis.A few tumour was hemorrhage and locally invasive.By immunochemistry stain,the tumor cells ex-pressed HMB45(+),S-100(+),MART-1(melan -A),Vimentin(+),CK(+),Ki -67(2% ~10% +), EMA(-),PR(-),GFAP(-),Syn(-),NSE(-),NF(-),A103(-).Conclusion:The melanocytomas in central nervous system is very rare and should be identification with schwannoma,meningioma,lipoma and hemangio-mas in MRI.Melanocytomas are isodense or hyperintense on T1 -weighted images and hypointense on T2-weighted images.The behaviour of most melancytomas in CNS is borderline or low grade malignant.The main treatment is surgi-cal resection.It may be confused with malignant melanoma,and other tumors with melanin differentiation.Diagnosis is based on iconography,histological characteristics and immunohistochemical findings.