Smith T W, Nikulasson S, De Girolami U, De Gennaro L J
Department of Pathology, University of Massachusetts Medical Center, Worcester 01655.
Clin Neuropathol. 1993 Nov-Dec;12(6):335-42.
Synapsin I is a phosphoprotein localized to the cytoplasmic surface of synaptic vesicles and is one of the best characterized neuron-specific proteins. Synaptophysin is an integral membrane glycoprotein, also located on presynaptic vesicles, which has been shown to be a useful immunohistochemical marker for neuroendocrine/neuronal differentiation in tumor diagnosis. The sensitivity and specificity of immunohistochemical staining for these two proteins in formalin-fixed, paraffin-embedded tissues was studied in a series of 67 neuroectodermal, neuroendocrine, and non-neural tumors. Intense immunoreactivity for both synapsin I and synaptophysin was observed in tumors containing well-differentiated neurons (gangliocytoma, ganglioglioma, neurocytoma). In these tumors, immunostaining was primarily concentrated along the outer surface of the cell membrane of the neuronal cells. Primitive neuroectodermal tumors (PNETs) (cerebral PNET, medulloblastoma, neuroblastoma) and most neuroendocrine tumors generally showed less intense and more variable immunoreactivity for these proteins. In most cases, immunostaining for synapsin I was sharper and often more intense than for synaptophysin. Some PNETs and neuroendocrine tumors that were immunoreactive for synapsin I did not stain for synaptophysin. We conclude that synapsin I is a reliable, sensitive immunohistochemical marker for neuronal/neuroendocrine differentiation in human neoplasms and may offer some advantages over synaptophysin when applied to formalin-fixed, paraffin-embedded tissues, particularly in the evaluation of primitive neuroectodermal tumors and neuroendocrine tumors.
突触素I是一种磷蛋白，定位于突触小泡的胞质表面，是特征最明确的神经元特异性蛋白之一。突触素是一种整合膜糖蛋白，也位于突触前小泡上，已被证明是肿瘤诊断中神经内分泌/神经元分化的一种有用的免疫组织化学标志物。在一系列67例神经外胚层、神经内分泌和非神经肿瘤中，研究了这两种蛋白在福尔马林固定、石蜡包埋组织中的免疫组织化学染色的敏感性和特异性。在含有高分化神经元的肿瘤（神经节细胞瘤、神经节胶质瘤、神经细胞瘤）中观察到突触素I和突触素均有强烈的免疫反应性。在这些肿瘤中，免疫染色主要集中在神经元细胞膜的外表面。原始神经外胚层肿瘤（PNETs）（脑PNET、髓母细胞瘤、神经母细胞瘤）和大多数神经内分泌肿瘤通常对这些蛋白显示出较弱且更可变的免疫反应性。在大多数情况下，突触素I的免疫染色比突触素更清晰，且通常更强。一些对突触素I有免疫反应性的PNETs和神经内分泌肿瘤对突触素不着色。我们得出结论，突触素I是人类肿瘤中神经元/神经内分泌分化的可靠、敏感的免疫组织化学标志物，当应用于福尔马林固定、石蜡包埋组织时，可能比突触素具有一些优势，特别是在评估原始神经外胚层肿瘤和神经内分泌肿瘤时。
