Sarcoid polyneuropathy masquerading as chronic inflammatory demyelinating polyneuropathy

Sarcoid polyneuropathy is a rare and clinically heterogeneous disorder that may be the initial presentation of sarcoidosis. Methods We report the clinical, electrophysiological, and pathological findings of a patient who carried a diagnosis of sensory‐predominant chronic inflammatory demyelinating polyneuropathy (CIDP) for over a decade but was ultimately found to have sarcoid polyneuropathy. Results A 36‐year‐old man presented with a several‐week history of gait difficulty and muscle cramps. He had a diagnosis of CIDP but had not received lasting benefit from steroid‐sparing immunosuppressive drugs. Electrodiagnostic studies were consistent with a chronic demyelinating polyradiculoneuropathy with conduction blocks. After he developed systemic symptoms, tissue biopsies revealed granulomatous disease. Symptoms improved with steroid therapy. Conclusions Sarcoid polyneuropathy presents a diagnostic challenge, but, in patients with atypical neuropathy, characteristic systemic symptoms, or a poor response to standard treatment, nerve and muscle biopsies can help diagnose this treatable disorder. Muscle Nerve 52: 664–668, 2015