POEMS syndrome: A case report.

POEMS syndrome is a rare multisystem disorder caused by a monoclonal plasma cell neoplasm, characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes. Due to its overlapping features with other neuropathies, diagnosis is often delayed, impacting prognosis. We report a 37-year-old male presenting with progressive limb weakness, inguinal lymphadenopathy, and spinal nerve root enhancement. Imaging revealed mixed lytic-sclerotic bony lesions, lymphadenopathies, hepatosplenomegaly, and spinal nerve root thickening and enhancement, which raised early suspicion for an underlying plasma cell dyscrasia rather than an isolated inflammatory neuropathy. Electrodiagnostic studies showed subacute demyelinating polyradiculoneuropathy with axonal degeneration, and laboratory findings included hypoalbuminemia, anemia, and thrombocytosis. A biopsy from the lymphadenopathy confirmed mixed plasma cell and hyaline vascular type Castleman disease, establishing POEMS syndrome in the context of a systemic plasma cell disorder. This case highlights how characteristic combinations of nerve root enhancement and mixed lytic-sclerotic bone lesions on MRI and CT can contribute uniquely to early diagnosis and differentiation from mimics such as chronic inflammatory demyelinating polyradiculoneuropathy or leptomeningeal disease, enabling prompt initiation of clone-directed therapy. Increased awareness of these imaging patterns among clinicians is critical for timely diagnosis and management.