婴儿色素性神经外胚层瘤的临床病理观察

Clinicopathological Features of Melanotic Neuroectodermal Tumor of Infancy.

目的:结合文献探讨婴儿色素性神经外胚瘤的临床病理特征。方法:对患儿左上颌骨肿物组织标本进行HE染色,并采用免疫组化S-P法检测肿瘤细胞的CK、S-100、Syn、NF、GFAP、HMB45、Ki67的表达情况。结果:肿瘤含两种主要成份:立方形上皮样细胞和神经母细胞。上皮样细胞呈腺管、腺泡样或条索状、片状,胞浆内含(中枢神经)黑色素颗粒。神经母细胞呈巢状,细胞间有多少不等神经微丝。免疫组化显示:神经母细胞Syn(+),S-100(+),GFAP(+),NF(+),上皮样细胞CK(+),K i67(+)阳性细胞约占5%-10%,HMB45(-)。结论:婴儿色素性神经外胚层瘤是非常罕见的肿瘤,是属于PNET类肿瘤的一种,具有神经内分泌的表现,属于良性肿瘤,但具有局部侵袭性。

Objective： To report one case of Melanotic neuroectodermal tumor of infancy （MNTI） occurred in the maxilla, investigate its immunohistochemical feature and review the literatures related to MNTI. Methods： The tumor was taken from left maxillary region in a six months old girl. Sections were prepared and stained with hematoxylin and eosin. S - P immunohistochemical staining was used to datect CK, S - 100, Syn, NF, GFAP, HMB45 and Ki67 in tumor cells. Resuits： The tumor is moderately vascularized, highly pigmented and solid, with fibrous connective tissue. There are usually two main types of cells： the first is large, cuboidal, epithelial - like cell with abundant, vacuolated cytoplasm and large ovoid sharply marginated nucleus; the second one is small and immature with hyperchromatic nucleus and nonpigmented cytoplasm. We also can see some small, but stellate, resembling a fibroblast. The tumor cells are divided into islands with slit -like alveoli, which are irregular in shape and size. Mitoses, pleomorphism, and other findings of anaplasia are not seen in this kind of tumor. Immunohistochemical staining of the small and immature cells are usually positive for Syn, S - 100, glial fibrillary acidic protein （GFAP） and NF. The epithelial - like cells are positive for cytokeratin （ CK）, and about 5% - 10% cells are positive for Ki67. The tumor cells are negative for HMB45. Conclusion： MNTI belongs to the primative neuroectedermal tumor （PNET） and has the immunohistochemical staining of neural iucretion. Although being considered as benign, MNTI is locally aggressive.