Ⅱ型巨指症神经脂肪浸润的病理改变

Pathologic Characters of the Nerve with Adipose Infiltration in Type Ⅱ Macrodactyly

目的研究Ⅱ型巨指症患者增粗神经的超微结构与功能蛋白表达。方法以多指正常结构指神经为对照,电镜下观察Ⅱ型巨指症患者增粗神经的超微结构;免疫荧光染色评价S100、LN和H3K27me3的表达水平。结果在巨指症增粗神经中,有髓神经纤维数目显著减少,部分有髓纤维的髓鞘板层结构皱缩、破坏,施万细胞的数量无明显改变。在巨指和正常对照的神经纤维中,S100的表达没有显著差异;LN在正常指神经中,呈现弥散表达或低表达,而在部分巨指增粗神经中为点状阳性表达;H3K27me3在巨指增粗神经组织和正常指神经组织中均为阳性表达。结论Ⅱ型巨指症神经纤维瘤病变为良性增生,部分髓鞘损害;机体可以功能代偿。因此,临床需根据患者神经的损伤与代偿情况,选择Ⅱ型巨指症神经的保留或切除。

Objective To explore the ultra-structural changes and functional protein expression of enlarged nerves in patients with type Ⅱ macrodactyly. Methods The ultra-structure of the enlarged nerves in type Ⅱ macrodactyly patients was observed under electron microscope. The expression of S100, LN and H3K27me3 were evaluated by immune-fluorescence staining. Normal digital nerves from polydactyly patients were used as control. Results The number of myelinated fibers was significantly decreased, and some myelinated lamellar structures were shrunk and destroyed. The number and morphology of Schwann cells did not change significantly. There was no significant difference in the expression of S100 between the macrodactyly group and control group. LN was low expressed in the normal digital nerve, and in the enlarged nerve samples, LN showed a stronger expression. In addition, the expression of H3K27me3 in both enlarged nerve tissue and normal nerve tissue were positive. Conclusion The neurofibromatosis of type Ⅱ macrodactyly is benign hyperplasia. In patients with type Ⅱ macrodactyly, the sheath of the enlarged nerves was damaged. However, LN positive staining indicates a repair mechanism to compensate for nerve injury. Therefore, the neurosurgical procedures should be determined according to the neurological damage and compensatory situation in patients in type Ⅱ macrodactyly.