Case report highlights diagnostic challenges between POEMS syndrome and CIDPMisdiagnosis of rare nerve disorder highlights need for vigilance

POEMS syndrome is a rare multisystem disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein (M-protein) secretion, and skin changes. Its pathogenesis is driven by plasma cell dyscrasias and the dysregulation of vascular endothelial growth factor (VEGF). In contrast, chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated condition that primarily affects peripheral nerve myelin, lacking the systemic involvement and hematological markers characteristic of POEMS syndrome. Given their overlapping neuromuscular manifestations—primarily progressive sensory loss and motor weakness—POEMS is frequently misdiagnosed as CIDP during initial presentation. This report presents a case of POEMS syndrome initially presenting with lower limb paresthesia. Through evaluation of the clinical course, specialized laboratory findings, and histopathological analysis, the diagnosis was clarified. By integrating this case with a comprehensive literature review, our study aims to enhance clinical vigilance and diagnostic accuracy in distinguishing POEMS syndrome from CIDP, two disorders with superficially similar neuropathic features but fundamentally different underlying etiologies.