Multiple ectopic germinomas presenting as focal dystonia of fingers: a case report and literature review

Background Intracranial primary germinomas predominantly develop on or near the midline structure in children and young adults and are diagnosed by brain imaging and biopsy. However, if brain imaging and pathology show unusual findings, it becomes difficult to make an accurate diagnosis. Case report Herein, we report the case of a 14-year-old boy who presented with focal dystonia of the fingers as an initial symptom. Magnetic resonance imaging of the brain showed multifocal heterogeneous lesions with solid and cystic components involving the right frontal lobe, corpus callosum, left basal ganglia, and left corona radiata. A stereotactic biopsy of the right frontal lesion revealed several granulomatous areas with abundant inflammatory cells. After immunohistochemical staining, the patient was diagnosed with germinoma and treated with chemoradiotherapy according to the Korean Society for Pediatric Neuro-Oncology protocol. The patient has been in complete remission for five years. Conclusion Germinomas can develop in intracranial off-midline structures, with unusual clinical, radiological, and pathological presentations. It is important to include intracranial germinomas in the differential diagnosis of infiltrative parenchymal tumors, especially in children.