A rare presentation of POEMS syndrome on magnetic resonance neurography: a case series

Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS) syndrome is a multisystem disease associated with underlying plasma cell neoplasm. Here, we present two cases of POEMS syndrome that manifested on magnetic resonance neurography as an increasing bone mass with cortical disruption, direct invading nerve roots and lumbar gluteal muscles. These features have not been previously reported. We also report a case with diffuse hypertrophy and enhancement of the brachial and lumbosacral plexus, which mimics the most common chronic inflammatory demyelinating polyradiculoneuropathy. Moreover, we detected perineurium effusions in the plexus, coupled with a variety of myofascitis and atrophy in denervated muscle. The case series is of concern to atypical magnetic resonance imaging findings of POEMS syndrome in the bone and peripheral nerve system as critical attacked target organs, which would be facilitating diagnosis.