Abstract
Background Sarcoidosis is a systemic disorder of unknown origin characterized by noncaseating granulomas. Clinical symptoms due to central nervous system (CNS) involvement occur in 5 to 7% of all cases; subclinical involvement is more frequent. Sole CNS involvement is very rare. Case Report A 25-year-old man presented with increasing polyuria and polydipsia over 8 weeks. Magnetic resonance imaging (MRI) revealed a supra- and infra-chiasmatic pre-thalamic mass lesion 1.0 × 1.4 × 1.4cm in diameter. Microsurgical biopsy verified a necrotizing noncaseating epithelioid cell tumor indicative for neurosarcoidosis. All symptoms dissolved within 3 months under stringent corticoid therapy. Conclusion Intracranial mass lesions as the primary and only manifestation of neuronal sarcoidosis are rare. Because conservative treatment is safe and effective, surgery is limited to biopsy and the alleviation of pressure-related symptoms to preserve neurologic function.