Prenatal diagnosis and genetic discoveries of an intracranial mixed neuronal-glial tumor

BACKGROUND Congenital intracranial tumors as a group are quite rare, representing only 0.5% to 1.5% of all pediatric brain neoplasms. CASE REPORT We reported a case of congenital mixed neuronal-glial tumor detected by ultrasound at 30 weeks of gestation. It showed that the tumor was 2.5 × 2.3 × 2.1 cm in size, located in the sellar region, regular shape, and slightly heterogeneous solid mass with a little cystic component. No color flow was present inside the tumor, but the peripheral encirclement by arterial circle of Willis. No other associated malformations were detected. Prenatal magnetic resonance imaging (MRI) which was taken subsequently confirmed the result of ultrasound and provided more detailed information such as fetal brain dysplasia.The fetal chromosomal karyotype analysis is normal. Single-nucleotide polymorphism (SNP)-based chromosomal microarray analysis (CMA) detected a 0.72-Mb duplication at 4q35.2 in fetus which was associated with epilepsy and cardiac anomalies. It also revealed a 0.13-Mb deletion at 6q26 located in PARK2 gene, and the mutation of the gene is known to be related to autosomal recessive juvenile Parkinson disease.The parents chose termination of pregnancy (TOP). The histological examination showed a mixed neuronal-glial tumor. CONCLUSION Prenatal detection of mixed neuronal-glial tumor is very rare. Ultrasound is of critical importance to detect the intracranial tumors, and MRI can give us some detailed information about the tumors. However, the precise histologic type was depended on the pathological examination. CMA should be necessary for the fetuses with congenital intracranial tumors, especially when the fetal chromosomal karyotype analysis is normal.