Leptomeningeal Enhancement due to Neurosarcoidosis Mimicking Malignancy.

The present report describes the case of a 56-year-old African American man experiencing progressive disequilibrium, lower extremity weakness, difficulty walking, and hearing loss. Brain magnetic resonance imaging showed leptomeningeal enhancement. Initial differential diagnosis was broad, including malignant, infectious, and inflammatory etiologies. The cerebrospinal fluid analyses demonstrated lymphocytic pleocytosis, hypoglycorrhachia, and hyperproteinorrachia but no other abnormalities. An extensive infectious disease workup was negative. Positron emission tomography revealed hypermetabolic lymph nodes in the right mediastinum and right hilum, correlating with findings on endobronchial ultrasonography. Subsequently, image-guided fine-needle aspiration of the right upper paratracheal lymph node was performed, and biopsy studies showed noncaseating granulomatous inflammation. Based on the clinical picture, the diagnosis of neurosarcoidosis was made, and high-dose steroids were started and resulted in significant improvement.