Occurrence of basal ganglia germ cell tumors without a mass.

Objective: To report a case series in which basal ganglia calcifications without mass effect proved to be germ cell tumors.
Design: Case series.
Setting: Tertiary care hospital.
Patients: Four patients.
Interventions: Computed tomography, magnetic resonance imaging, positron emission tomography, biopsy, chemotherapy, and radiation therapy.
Main Outcome Measures: Recognition of clinical syndrome and radiological features.
Results: All patients had progressive hemiparesis, and 1 patient also had frontal lobe dementia. Imaging demonstrated progressive asymmetric signal abnormality with basal ganglia calcification and associated brainstem atrophy. Fludeoxyglucose F 18-positron emission tomography showed hypometabolism in contrast to malignant glioma.
Conclusion: Germ cell tumor should be considered in patients with an indolently progressive neurological course, particularly if basal ganglia calcification is present with or without enhancement, asymmetric brain atrophy, or a mass.