A case report of neurosarcoidosis mimicking Guillain-Barré syndrome: the diagnostic utility of skin biopsy in neurosarcoidosis

We report a compelling case of neurosarcoidosis in a 74-year-old Japanese woman. She initially presented with a clinical course that closely mimicked Guillain-Barré syndrome (GBS), and the definitive diagnosis of neurosarcoidosis was eventually made through a skin biopsy. The patient presented with progressive limb weakness and sensory disturbances and was initially treated for a presumptive diagnosis of GBS. Although her condition showed an initial temporary improvement, her symptoms subsequently relapsed and worsened. This atypical and relapsing clinical pattern prompted a comprehensive systemic workup to find an alternative diagnosis. Based on the histological findings on skin biopsy and the clinical presentation, a diagnosis of probable neurosarcoidosis was made. This case highlights the importance of considering neurosarcoidosis in the differential diagnosis of GBS with an atypical course. A comprehensive systemic workup is crucial for such cases. It further emphasizes that a thorough systemic evaluation is essential for accurate diagnosis, as a simple and accessible procedure like a skin biopsy can provide essential histological evidence to support the diagnosis.