Neurosarcoidosis presenting as a tumour of the basal ganglia and brainstem: sequential MRI.

Neurosarcoidosis may spread from the basal leptomeninges via the Virchow-Robin spaces to form intraparenchymal masses. We present a case of sarcoidosis whose first presentation was that of secondary amenorrhoea without other neurological symptoms. Discovery of a mass invading the basal ganglia, hypothalamus, pituitary stalk and midbrain led to a search for systemic involvement. After the diagnosis was proven by mediastinal biopsy, steroids were used effectively to shrink the tumour. Sequential magnetic resonance imaging (MRI) studies demonstrate dramatic reduction in the mass over a six month period. A high index of suspicion for sarcoidosis in intracranial masses, particularly in young adults, is advocated.