婴儿黑色素神经外胚瘤(MNTI)是国际公认的一种罕见疾病。就我们所知,自1918年由Krompecher首先报告此瘤至今,国外仅有90余例报告,国内只有极少个案报告。我院1970年以后,在临床上曾诊治两例经病理检验确诊为这一种瘤的患儿,并对其中一例手术切除的瘤块进行了超微结构研究。肿瘤组织在电镜下可见两种细胞群,一种是含黑色素的细胞,另一种是无黑色素的小园细胞。色素细胞呈多角或长梭形,彼此以上皮连接方式相连,形成细胞团或围成腔隙。有时可见基底膜将有色素的细胞包围。有色素细胞的胞核富于斑块状异染色质,核膜边缘不齐,胞浆比较丰富。胞浆内除见有线粒体、粗面内质网和高尔基复合体外,还存在许多处在不同发育阶段(Ⅱ—Ⅳ期)的黑色素小体。这些小体为园形或呈棒状,常可在棒状小体 Infantile melanoma neuroepithelial neoplasia (MNTI) is an internationally recognized rare disease. As far as we know, since Krompecher first reported this tumor in 1918, only 90 cases have been reported abroad, and only a few cases have been reported in China. Since 1970 in our hospital, we have diagnosed and treated two cases of children diagnosed as this type of tumor by pathological examination, and performed ultrastructural studies on one of the surgically removed tumor masses. The tumor tissue can be seen under the electron microscope in two cell populations, one is melanin-containing cells and the other is melanin-free small garden cells. Pigment cells are polygonal or long shuttle-shaped, connected to each other by way of skin connection, forming a group of cells or forming a cavity. It is sometimes seen that basement membranes surround pigmented cells. The nucleus of pigmented cells is rich in plaque-like heterochromatin, and the edges of nuclear membranes are uneven, and the cytoplasm is abundant. In addition to mitochondria, rough endoplasmic reticulum and Golgi complex in cytoplasm, there are many melanosomes at different stages of development (phase II-IV). These bodies are round or rod-shaped, often in rod-shaped bodies