Oral Mucosal Melanoma: Some Pathobiological Considerations and an Illustrative Report of a Case

Oral mucosal melanoma is a relatively rare malignancy with an aggressive clinico-pathological behaviour. The mean 5-year survival rate is about 15 %. It arises primarily from melanocytes found in the basal cell layer of the epithelium, but may sometimes arise from melanocytes residing in the lamina propria. The pathogenesis is complex, and few of the molecular mechanisms underlying the development of oral mucosal melanoma have been defined. The extraneous risk factors associated with oral mucosal melanoma, if any, are unknown. Oral mucosal melanomas account for about 25 % of all mucosal melanomas of the head and neck, and exhibit a profile of cytogenetic alterations, and a pathobiological behaviour and clinical course different from that of cutaneous melanomas. As they are usually painless and grow quickly, as a rule, they are diagnosed late in the course of the disease when the lesions are already large and have metastasized to regional lymph nodes. In this paper we discuss some aspects of the pathobiology of oral mucosal melanoma, and present an illustrative case report.     

白癜风患者血清中抗黑素细胞IgG,IgM抗体的检测及补体介导的血清细胞毒反应

为探讨白癜风血清中的抗黑素细胞抗体类型和反应模式以及对黑素细胞的损伤作用 ,以免疫组化法检测了白癜风患者血清中抗黑素细胞IgG、IgM抗体 ,并以吖啶橙 /溴化乙锭细胞染色法观察补体介导的白癜风血清对黑素细胞损伤作用。结果发现 2 5例活动性寻常型白癜风患者血清中有 19例检出IgG型抗体 ,2 1例检出IgM型抗体 ,明显高于稳定期和正常对照组血清 ;2 5例活动期血清 9例出现对黑素细胞的明显细胞毒作用 ,高于正常人血清 ,对照的成纤维细胞未出现明显的细胞毒作用。结果提示白癜风患者血清内有抗黑素细胞IgG、IgM抗体 ,这些抗体可以通过补体选择性的损伤体外培养的黑素细胞 ,支持白癜风是一种自身免疫性疾病的假设。     

性别决定区盒基因10在黑素瘤中的研究现状及进展

研究表明调节发育过程的基因与通过增殖、侵袭和转移介导肿瘤进展的基因之间存在越来越多的相关性,而针对这些基因的靶向治疗成为当前研究的热点。性别决定区盒基因10(SOX10)是发育生物学中的一个重要转录因子,不仅对黑素细胞的发育及分化产生影响,在黑素瘤的存活、增殖和侵袭中也发挥着重要的作用。现就SOX10在黑素细胞发育和黑素瘤中的作用进行综述,并探讨SOX10在黑素瘤治疗中的潜在方向和前景。     

白癜风皮损区角朊细胞对黑素细胞影响的观察

采用细胞培养的方法，观察了角朊细胞（ＫＣ）对黑素细胞（ＭＣ）的影响以及白斑区ＫＣ对正常ＭＣ的可能作用．结果发现，只有当ＫＣ与ＭＣ发生接触时ＫＣ对ＭＣ才发生显著的影响，支持ＫＣ与ＭＣ接触是两者发生相互影响前提的观点．未发现节段型白癜风不同病期白斑区的ＫＣ对正常ＭＣ有明显的异常作用     

白细胞介素—6对人表皮黑素细胞活性及黑素合成的调控抑制研究

白细胞介素－６（Ｉｎｔｅｒｌｅｕｋｉｎ－６ＩＬ－６）具备多种细胞生物学效应，也属一种表皮细胞因子。本实验在体外建立了表皮黑素细胞培养基础上，观察不同浓度ＩＬ－６对表皮黑素细胞代谢活性，酪氨酸酶活性和黑素合成的影响。结果表明，微量ＩＬ－６（１０Ｕ／ｍｌ）在４８ｈ内即抑制表皮黑素细胞代谢活性，而酪氨酸酶活性和黑素合成随ＩＬ－６剂量升高呈明显剂量依赖性抑制效应。提示该类细胞因子作用可能与黑素合成有关的恶性黑色素瘤及Ｐａｒｋｉｎｓｏｎｓ病密切相关。     

Clinical, microscopic and ultrastructural alterations due to mustard gas poisoning

Yperite, as a chemical weapon, is responsible for severe cutaneous alterations. In this article we review the clinical aspects of mustard gas poisoning and present the electron microscopic changes found in the epidermis and superficial dermis. Sublethal and lethal alterations were present in keratinocytes and melanocytes. Other cytological aspects indicated attempts at cell division and increased metabolic activity. Some atypical features raise the possibility of mutagenesis.     

Expression of different immunological markers by cultured human melanocytes

The expression of different immunological markers by cultured human melanocytes (MC) in relation to immune phenomena, were investigated on ten different MC cell lines from early (1st) to late (22nd) passage. Four melanocyte lines (MC-a) which had undergone changes in growth behaviour during prolonged culture were included in the study, together with two melanoma lines. Cytospin preparations of the cells were stained for the presence of a set of different immunological markers and a melanoma-associated antigen (MAA). All MC lines, including the MC-a and the melanoma lines, showed expression of MHC class I, IL-1, IL-2, ICAM-1 and the MAA, NKI-Beteb, during all passages tested. Interestingly, four of the MC lines showed staining for the Fc receptor. A tendency towards a stronger expression of ICAM-1 on a higher percentage of cells was observed on MC with increasing passage number, the MC-a and the melanoma lines. Expression of the MAA was strongly reduced for the MC-a lines in comparison with the MC and the M14 melanoma lines. Positive staining for the HLA class II molecules was obtained on MC of intermediate and late passages, and on the MC-a and the melanoma lines in the decreasing order HLA-DR, DP and DQ. Additionally, we carried out a preliminary study showing that cultured MC also produce IL-1 and IL-6. However, we were not able to show the production of biologically active IL-2 testing several cultured MC lines. Nevertheless, the overall results taken together suggest that MC are immunologically important cells that are susceptible to changes during long-term culture.Part of this work was presented at the third ESPCR Meeting, Amsterdam, the Netherlands in 1991 and at the 53rd Annual Meeting of the SID in Baltimore, Maryland, USA, in 1992     

Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion

This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn. Received: 13 January 2000 / Accepted: 27 March 2000