Bilateral basal ganglia germinoma in an adolescent presenting with cerebral hemiatrophy

*Correspondence: [e-mail].

Abstract

Case Presentation: A previously healthy 16-year-old adolescent developed subacute behavior change characterized by depressed mood. Four months later she presented progressive proportionate right hemiparesis associated with polydipsia and polyuria symptoms. In the following months, she started with amenorrhea, dysphagia, dysarthria and slowly progressed to important cognitive impairment. One year after the onset of symptoms, the patient was admitted to our service. Her first neurological examination showed poor language, pseudobulbar affect, dysarthria and proportionate right hemiparesis with bilateral pyramidal tract signs. Brain MRI showed: periventricular bilateral infiltrative lesion, hyperintense in T2/FLAIR with heterogeneous enhancement and perilesional edema associated with marked left frontal lobe and striated nucleus hemiatrophy. Germ cell tumor of the basal ganglia was suspected. Her alpha-fetoprotein and human chorionic gonadotropin in the serum were normal and biopsy confirmed primary germinoma. She was put on chemoradiotherapy and although motor sequelae persisted, a 5 year recurrent-free condition was achieved.

Discussion: Germinoma is the most common intracranial germ cell tumor and usually arises from the midline. Basal ganglia germinomas are a rare entity, representing only 5-10% of all germinomas. These tumors are usually unilateral, and bilateral occurrence is extremely rare. It has a slow clinical course characterized by hemiparesis, neuropsychiatry symptoms, endocrinological changes, oculomotor palsy, speech or visual disturbance. The diagnosis is suggested by peculiar neuroimage findings: one third of the patients present with cerebral and/or brain stem atrophy and usually image hyperintensity is commonly seen in T1 and T2-weighted images. Hemiatrophy can be subtle and occur prior to clinical manifestation. It has been hypothesized that the phenomenon of ipsilateral cerebral hemiatrophy is caused by wallerian degeneration of efferent and afferent fibers from the basal ganglia and thalamus due to destruction of ganglia cells and nerve fibers caused by the tumor and the consequent interruption of thalamocortical connections.

Final Comments: We report a rare case of bilateral basal ganglia germinoma. We recommend that this entity should be suspected in cases presenting with basal ganglia focal lesion, progressive hemiparesis, behavior symptoms and ipsilateral cerebral or brain stem hemiatrophy, aiming for an early diagnosis and treatment to reduce morbimortality.

 

MissingLinkText

Publication History

Article published online:
12 May 2025