[High-grade gliomas with H3 G34R mutation: a clinicopathological study].

Objective: To analyze the clinicopathological features and probable mechanisms of high-grade gliomas with H3 G34R mutation. Methods: Five cases of high-grade gliomas with H3 G34R mutation were collected at Xuanwu Hospital, Capital Medical University, Beijing, China, from 2016 to 2019. The clinical and pathological data for each case was retrospectively reviewed. Results: The 5 patients (2 males and 3 females) aged from 15 to 45 years (mean 23 years), and had a history of headache or motor weakness. Four of them were younger than 20 years of age. Magnetic resonance imaging showed that the lesions of 3 cases were seen separately in frontal lobe, parietal lobe or temporal lobe, 1 case involved both frontal lobe and parietal lobe, and otherwise multiple lobes were involved in 1 case. Contrast enhancement could be observed in 2 cases. Pathological examination showed that glioblastoma was the most common entity, with or without primitive neuronal component. All 5 cases showed that H3 G34R was diffusely positive in tumor nuclei with ATRX loss. Moreover, p53 was overexpressed in 4 cases. None of them showed Olig2 expression. Two patients showed disease progression after surgery at 18 months and 24 months, respectively. The latter of the two deceased 3 months after tumor progression. Conclusions: The clinicopathological and molecular genetics features of high-grade gliomas with H3 G34R mutation have relatively similar clinicopathological and genetic features, and more commonly seen in young adults (vs. older adults). Thus, these tumors may be discussed further as a distinct tumor entity.目的： 探讨伴有H3 G34R突变的高级别胶质瘤的临床病理学特点，分析其可能的发生机制。 方法： 收集首都医科大学宣武医院病理科2016—2019年经组织病理学及基因检测确诊为伴有H3 G34R突变的高级别胶质瘤5例，分析其临床、影像学特征及病理学特点，并结合相关文献复习。 结果： 5例患者中男性2例，女性3例。年龄15~45岁（平均年龄23岁），其中小于20岁患者4例。5例患者均以头痛或肢体乏力起病。影像学提示病变单独位于额叶或顶叶者各1例，同时累及额叶及顶叶者1例，单独累及颞叶者1例，弥漫累及多脑叶者1例；其中2例存在轻度病灶强化。形态上，5例均为胶质母细胞瘤结构，其中2例伴有原始神经元成分；全部5例肿瘤细胞均表达H3 G34R突变型抗体并伴有ATRX表达缺失，除1例外均出现p53过表达，5例均不表达Olig2。2例患者分别于术后18和24个月复发，后者于复发后3个月死亡；另3例术后不足12个月的患者目前无进展。 结论： 伴有H3 G34R突变的高级别胶质瘤在临床病理学和分子遗传学方面均具有相对一致的特征，包括其显著好发于年轻患者，发生部位几乎全部位于大脑半球，其组织学类型以胶质母细胞瘤最为常见等。可以考虑将其作为新的肿瘤实体进一步加以研究。.