Chronic inflammatory demyelinating polyradiculoneuropathy with diffuse and massive peripheral nerve hypertrophy: distinctive clinical and magnetic resonance imaging features.

We present 3 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with extensive and diffuse hypertrophy of the nerve roots and peripheral nerves. They exhibited slowly progressive sensory impairment and distally predominant limb weakness and muscular atrophy, and markedly enlarged palpable nerve trunks. They responded beneficially to corticosteroid. Magnetic resonance imaging demonstrated diffuse and extensive hypertrophy of the peripheral nerves in the four limbs and the spinal nerve roots, with gadolinium enhancement in the nerve roots but not in the peripheral nerves. These patients were considered to have a hypertrophic variant of CIDP.