恶心黑色素瘤
【概述】
恶性黑色素瘤来源
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恶心黑色素瘤 【概述】 恶性黑色素瘤来源于黑色素细胞,与黑色素细胞的转化有关,神经嵴上皮产生黑色素细胞。发病率随年龄上升,在儿童发病率几乎为零。恶性黑色素瘤好发于皮肤。 The most dangerous form of skin cancer, these cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumors. These tumors originate in the pigment-producing melanocytes in the basal layer of the epidermis. Melanomas often resemble moles; some develop from moles. The majority of melanomas are black or brown, but they can also be skin-colored, pink, red, purple, blue or white. Melanoma is caused mainly by intense, occasional UV exposure (frequently leading to sunburn), especially in those who are genetically predisposed to the disease. Melanoma kills an estimated 9,710 people in the US annually. If melanoma is recognized and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths. The American Cancer Society estimates that at present, more than 120,000 new cases of melanoma in the US are diagnosed in a year. In 2014, an estimated 76,100 of these will be invasive melanomas, with about 43,890 in males and 32,210 in women. 【病理】 从大体上盾,一般瘤体呈扁平或球形,结节状,或菜花状、蕈状,孤立肿块,周围常伴卫星小结。色深红或灰红,灰褐,质地脆。切面观,肿块无清楚境界,常向四周侵犯。 【临床表现】 临床上分四型:①浅表扩展型:最常见的类型,约占50%-70%。多在色素痣的基础上发生,病情缓慢,而后突然生长加快。通常色素加深明显,分布不均。表面和边缘不规则,微隆起,部分呈结节状。②结节型:此型约占15%~45%。垂直生长更具侵袭性,生长速度快,通常恶性程度高。组织学上从表皮向真皮垂直生长而无水平生长部分。肿块为蓝黑色,但也可以是无色的。通常为息肉样块,有时像菜花状,或似血泡呈血管瘤样。③雀斑型:此型约占4%-12%。转移倾向较低。多位于面、颈部,为生长多年的略高出皮面的色素病灶。部分区域可有结节,颜色不均,边缘不规则。④肢端雀斑型:此型少见。多在掌、跖部及甲下。甲床下病变不易与普通血肿相鉴别而延误治疗。 【诊断】 皮肤色素痣或粘膜色素斑有以下情况时,应视为恶变征象:①体积增大,生长加速;②色素增多或呈放射状扩展;③在肿瘤周围及基底有色素加深的增生浸润现象;④病变内或周围出现结节(卫星结节);⑤出现痒、痛感;⑥破溃,出血;⑦所属区域淋巴结突然增大。 主要依据色素表现及临床症状,不宜行活检,即使是转移性淋巴结亦不应作吸取活检,因活检可促使其加速生长,并使肿瘤播散发生远外转移。对无色素性黑色素瘤则临床诊断困难,有时只能在病理检查之后,才能确诊。临床上如不能区别是否为恶性黑色素瘤时,可行病灶冷冻活检,并争取一期完成治疗。一个先前存在的色素沉着,异常改变大小、厚度和颜色应怀疑恶性黑色素瘤。但必须强调大部分恶性黑色素瘤,特别是结节型是在健康皮肤发生的,活检是绝对必要的,最好是切除活检。如果初次是部分切除,必须行更大范围切除,应切除皮肤全层以行确切的病理解剖评估。 【治疗】 治疗原则如下:①手术治疗:以外科手术切除为主,对放疗不敏感。手术原则必须作广泛彻底切除,切除范围要比其他恶性肿瘤更广、更深。恶性黑色素瘤早期就有区域淋巴结转移,且转移率较高,应行选择性淋巴清扫术。②化疗:对恶性黑色素瘤有一定疗效的化学药物:二甲三氮烯唑酰胺、卡氮芥、羟基脲、放线菌素D、长春新碱等。采用局部动脉插管、静脉注射,作为手术前后的综合治疗。近年来多采用二甲三氮烯唑酰胺+卡氮芥+长春新碱联合应用。目前,化疗的效果还不理想。化疗+免疫即二甲三氮唑酰胺+卡介苗综合治疗可提高疗效。③免疫治疗:免疫治疗对恶性黑色素瘤有一定疗效。卡介苗可注射于肿瘤内、转移结节内、口服、皮内注射或大面积划痕,作为综合治疗的一部分。④冷冻治疗:色素细胞对低温十分敏感,冷冻治疗对恶性黑色素瘤原发灶有肯定疗效。