Abstract: Background：Timely diagnosis of primary intracranial germ cell tumors (ICGCTs) still posed a big challenge. Objective：To analyze the risk factors for delayed diagnosis of ICGCTs in children. Design：Case-control study. Methods：Children with ICGCTs were enrolled from Department of Pediatrics at Beijing Shijitan Hospital, Capital Medical University between October 2011 to April 2021. ICGCT children with the time from onset to diagnosis ≥ 6 months were taken as the delayed diagnosis group, and those with less than 6 months were put into the non-delayed diagnosis group. According to the reasons that cause delayed diagnosis, the delayed diagnosis group was further divided into disease group, family group, and diagnosis group. The demographic features, clinical manifestations and ancillary examinations were collected. Risk factors were established by univariate analysis and multivariate logistic regression analysis. Main outcome measures：Risk factors for delayed diagnosis of ICGCTs. Results：There were 114 males and 44 females in 158 children with ICGCTs．There were 88 cases in the non-delayed diagnosis group and 70 cases in the delayed diagnosis group including 15 cases in the disease group, 23 cases in the family group, and 32 cases in the diagnosis group. The most common primary symptoms were high intracranial pressure symptoms in the non-delayed diagnosis group, endocrine symptoms in the disease group and family group, and neuropsychiatric and endocrine symptoms in the diagnosis group. Multiple tumor lesions were mainly seen in the diagnostic group. In the non-delayed diagnosis group, there were more children with pathological type of NGGCTs, maximum diameter of tumor ≥3 cm, hydrocephalus, and need for ventriculoperitoneal shunt/third ventriculostomy. There are fewer children with β-HCG ≥5 mIU·mL -1 after at least 6 months of onset. Further analysis of the risk factors leading to delayed diagnosis found that endocrine symptoms were risk factors for delayed diagnosis in the family subgroup; the three main signs of high intracranial pressure and the maximum tumor diameter ≥3 cm were protective factors in the diagnosis subgroup; β-HCG ≥ 5 mIU·mL -1 was found after at least 6 months of onset was a risk factor for delayed diagnosis. Conclusions：The delayed diagnosis of ICGCTs is related to the characteristics of disease, the cognition of the child's family and the level of hospital treatment. An individualized diagnosis and treatment plan needs to be formulated.

Key words: Primary intracranial germ cell tumors, Delayed diagnosis, Risk factor, Prognosis, Child