A congenital infant-type hemispheric glioma case with EML4::ALK fusion.

Infant-type hemispheric glioma is a high-grade cellular astrocytoma that arises in the cerebral hemispheres in early childhood. It is characterized by receptor tyrosine kinase fusions, typically involving genes such as the NTRK family, ROS1, ALK, or MET. This tumor type represents a distinct diagnostic category in the fifth edition of the WHO Classification of Tumors of the Central Nervous System. Here, we present a congenital brain tumor case that developed in the left lateral ventricle with EML4::ALK fusion, and was classified as an infant-type hemispheric glioma. The patient was found to have hydrocephalus and a brain tumor in utero. Central pathologists made a diagnosis of high-grade anaplastic astrocytoma with EML4::ALK fusion. The patient underwent radical tumor resection and a combination of chemotherapies. She is now 7 years old and doing well with no recurrence. To our knowledge, this is the first report of a congenital intraventricular tumor with EML4::ALK fusion.