We present a 6-year-old boy with unilateral retinoblastoma of the left eye. MRI showed an intraocular tumor that extended into the optic nerve beyond the lamina cribrosa. The affected eye was enucleated and the optic nerve resection margin proved to be free. Following protocol, this patient received six courses of adjuvant systemic chemotherapy. Unfortunately, after 5 months this patient returned with the leptomeningeal spread of the tumor and died quickly thereafter.Histopathologic analysis of the enucleated eye and distal optic nerve revealed that the postlaminar tumor cells occupied the entire width of the optic nerve, extending all the way up to the pia mater, whereas, more often the tumor invasion is restricted to the center of the optic nerve. This was also visible on the MR images where contrast enhancement occupied the entire nerve width. A resection margin with tumor cells is recognized as a risk factor for metastasis, but perhaps the proximity of tumor cells to the leptomeninges should also be judged with caution as a potential increased risk for metastatic spread.

中文翻译：

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视网膜母细胞瘤的全层板层视神经肿瘤浸润是视网膜母细胞瘤脑膜扩散的危险因素。病例报告和文献复习。

我们介绍了一个6岁男孩左眼单侧视网膜母细胞瘤。MRI显示眼内肿瘤延伸至筛板之外的视神经。患眼摘除眼球，视神经切除边缘被证明是游离的。按照方案，该患者接受了六个疗程的辅助全身化疗。不幸的是，这名患者在5个月后恢复了肿瘤的全脑膜扩散并迅速死亡。对去核眼和远端视神经的组织病理学分析显示，椎板后肿瘤细胞占据了视神经的整个宽度，一直延伸到整个视神经。然而，更多时候，肿瘤的侵袭仅限于视神经的中心。这在MR图像上也可以看到，其中对比度增强占据了整个神经宽度。