T1 axial post gad T1 coronal post gad T1 coronal post gad

Diagnosis: Neurosarcoidosis

The CNS is affected in systemic sarcoidosis in up to 5% of all cases. The most common findings include enhancement in the basal leptomeninges with extension into the basal ganglia and thalami via the Virchow-Robins spaces. An enhancing hypothalamic mass or thickening with enhancement of pituitary infundibulum may also be seen. Neurosarcoidosis may very rarely present as a parenchymal mass. Leptomeningeal enhancement may also be seen in carcinomatosis, most often lung, breast or melanoma. Lymphoma, meningitis, prior subarachnoid hemorrhage, or surgery may also produce leptomeningeal enhancement. Langerhans cell histiocytosis is in the differential for hypothalamic mass or pituitary infundibular thickening and is more commonly seen in children.

The combination of leptomeningeal enhancement with a thickened pituitary infundibulum is most compatible with sarcoidosis although this was not biopsy proven. This patient had known systemic sarcoidosis. Related Cases

Neurosarcoidosis Langerhans cell histiocytosis Leptomeningeal carcinomatosis