Background: Pediatric intracranial aneurysms (IAs) are rare, with an estimated occurrence of less than 5% of all IAs. The pathology of pediatric aneurysms may differ from adult IAs and require additional workup. Management options for pediatric aneurysms include both endovascular and open procedures. The authors report the case of a 7-year-old male with a large, partially thrombosed distal middle cerebral artery (MCA) aneurysm.

Observations: The patient presented with left hemiparesis. The initial CT imaging showed an intraparenchymal hemorrhage (IPH) in the right frontal lobe. Digital subtraction angiography (DSA) showed a large, partially thrombosed distal MCA aneurysm. A right frontal craniotomy was performed for aneurysm clipping, excision, and hematoma evacuation. Intraoperative DSA was utilized to confirm the absence of residual aneurysm. At the 6-month follow-up appointment, the patient had returned to his neurological baseline. He continues annual cerebrovascular radiographic surveillance.

Lessons: Pediatric aneurysms presenting with IPH are exceedingly rare. In this patient, an open surgical intervention was favored due to the presence of an IPH and the distal location of the aneurysm. Pediatric aneurysms may have a different etiology than that of adults. Because of this difference, these lesions require special considerations with regard to workup and treatment. https://thejns.org/doi/10.3171/CASE24373.

Keywords: aneurysm; intraparenchymal hemorrhage; pediatric.

背景： 儿童颅内动脉瘤（IAs）较为罕见，估计占所有IAs的比例不足5%。儿童动脉瘤的病理可能与成人IAs不同，并且需要进一步检查。对于儿童动脉瘤的治疗选项包括血管内手术和开放式手术。作者报告了一例7岁男性患儿的大范围、部分血栓形成的远端大脑中动脉（MCA）动脉瘤的病例。

观察结果： 患者出现左侧偏瘫症状。初次CT成像显示右侧额叶有脑实质内出血（IPH）。数字减影血管造影（DSA）显示一个大范围、部分血栓形成的远端MCA动脉瘤。进行了右额部开颅手术，进行动脉瘤夹闭、切除和血肿清除。术中使用了DSA以确认没有残留的动脉瘤。在6个月后的随访检查时，患者的神经功能已恢复到基线水平。患者继续每年接受脑血管放射影像监测。

教训： 儿童颅内动脉瘤伴发IPH的情况极为罕见。在此病例中，由于存在IPH和动脉瘤位于远端位置，因此选择开放手术治疗。儿童动脉瘤可能与成人动脉瘤的病因不同，鉴于这种差异，这些病变在检查和治疗方面需要特殊考虑。

关键词： 动脉瘤；脑实质内出血；儿童。