图1 光学显微镜观察所见 HE 染色 ×400 1a 病灶周边可见胞核增大、内有胞核内包涵体的少突胶质细胞1b 病灶内可见多形性或多核的星形胶质细胞 图2 光学显微镜观察显示,受感染的少突胶质细胞胞核表达SV40 免疫组化染色(EnVision 二步法) ×200Figure 1 Optical microscopy findings HE staining ×400 Inclusion⁃bearing, enlarged nuclei in virally infected oligodendrocytes, sit at the periphery of demyelinated foci(Panel 1a). Nuclear hyperchromasia and pleomorphism of astrocytes were also evident (Panel 1b). Figure 2 Optical microscopy showed SV40 was positive in infected oligodendrocytes. Immunohistochemical staining(EnVision) ×200
进行性多灶性白质脑病是一种中枢神经系统脱髓鞘性疾病,由JC 病毒机会性感染所致。病变常位于灰白质交界处,髓鞘染色可见髓鞘脱失,病灶内特别是活动性病灶内有大量泡沫细胞,仅可见散在淋巴细胞浸润。受感染的少突胶质细胞胞核较大、深染,“毛玻璃”样改变的少突胶质细胞多见于病灶周边(图1a),病灶内及周围脑组织可见体积增大、深染、异形性或多核、胞质丰富的星形胶质细胞(图1b),组织活检或冰冻病理学检查易误诊为肿瘤细胞。免疫组化染色,受感染的少突胶质细胞胞核表达JC 和SV40(图2),高表达P53 和Ki⁃67。