原发性鼻腔鼻窦黏膜恶性黑色素瘤4例临床病理分析

Primary sinonasal mucosal malignant melanoma:a clinicopathologic study of 4 cases

目的探讨原发性鼻腔鼻窦黏膜恶性黑色素瘤(SMMM)的临床病理特点、鉴别诊断、治疗与预后。方法回顾性分析4例SMMM的临床病理资料,观察其组织形态特征及免疫组化特点,并复习相关文献。结果患者男性1例,女性3例,平均年龄75.5岁(65～90岁),临床主要表现为鼻塞、出血及鼻腔新生物,镜下瘤细胞形态多样,异型性较明显,以上皮样细胞和小圆细胞为主,伴有局部少量梭形细胞样细胞,仅部分显示黑色素。其中1例可见黏液样变,1例色素性黏膜恶性黑色素瘤局部复发后细胞体积明显增大,色素减少,多数细胞胞质透明,呈气球样变。免疫组化示HMB45、vimentin、S-100均不同程度(+),NSE、LCA、SMA、CD99和desmin(-),局部CK、CD68弱(+)各1例,Ki-67程度不一。结论鼻腔原发性黑色素瘤少见,恶性程度较高,形态多样,免疫组化对诊断及鉴别较为重要。

Objective To investigate the clinicopathologic characteristics,differential diagnosis,therapy and prognosis of primary sinonasal mucosal malignant melanoma.Methods With review of literature,the clinicolpathologic data were retrospectively analyzed while characteristics of morphology and immunohistochemisty of the tumor cells were observed in 4 patients with primary sinonasal mucosal malignant melanoma.Results The primary sinonasal mucosal malignant melanoma was diagnosed in 3 female patients and 1 male with mean age of 75.5（65-90） years.The clinical manifestation was nasal obstruction,epistaxis or neoplasm.Microscopically,the heteromorphism of the tumor cells was great and the morphologic features were various.The tumor consisted mainly of epithelioid cells and/or small round cells with local spindle cells.Melanin was noticed only in part of the cases and myxoid change was found in one case.Still we observed in one case that pigmented mucosal melanoma cells became bigger in size and hypopigmented with clear cytoplasm,so-called ＂balloon degeneration＂,after local recurrence.Immunohistochemisty showed that the tumor cells were all positive for HMB45,vimentin and S-100 protein in a varying degree,but NSE,LCA,SMA,CD99 and desmin negative,while focal and weak-positive expression of CK and CD68 was also noted in one cases,and Ki-67 expressied in a different level.Conclusion The primary sinonasal mucosal malignant melanoma is rare and highly heterogenous.The application of immunohistochemistry plays an important role in its diagnosis and differential diagnosis.