英语语法分析

Leptomeningeal melanosis is malignant in 40-50% of patients with neurocutaneous melanosis.

在40 - 50%的神经皮肤黑变病的患者中软脑膜黑色素沉着是恶性的。

Melanosis coli is mainly related with constipation and abuse of laxatives and possibly related with neoplasm.

结肠黑变病病因主要与便秘和服泻药有关，结肠黑变病与肿瘤可能有一定的关系。

Objective To analyze the pathogenesis endoscopic characteristic prevention and cure measures for melanosis coli.

目的分析结肠黑变病的病因、镜下表现及防治措施。