Abstract
Introduction POEMS syndrome is a rare paraneoplastic syndrome featuring polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell dyscrasia, and skin changes.
Case A previously well 44-year-old man presented with two days of a mild postural headache and two weeks of progressive sensory ataxia with symmetrical lower limb numbness and weakness. Examination revealed diffuse areflexia, multimodal distal lower limb sensory loss, and mild distal-predominant lower limb weakness. There was mild pedal odema but no significant skin or nail changes.
Imaging identified a right transverse sinus cerebral venous thrombosis and incidental pulmonary emboli. A large intensely PET-avid lytic lesion in the left iliac crest was found on PET/CT, along with a smaller PET-avid sclerotic lesion in the L4 vertebral body. Bloodwork revealed thrombocythaemia but normal haemoglobin, calcium, and renal function. Thyroid function and HbA1c were normal.
Nerve conduction studies confirmed a subacute length dependent mixed axonal and demyelinating sensorimotor peripheral neuropathy. Serum protein electrophoresis, including immunofixation, was twice negative for a paraprotein. Biopsy of the lytic lesion confirmed a lambda-restricted plasmacytoma. Bone marrow biopsy demonstrated atypical megakaryopoeisis but only scattered plasma cells. Serum vascular endothelial growth factor (VEGF) was markedly elevated at 1633 ng/L.
Diagnostic criteria for POEMS syndrome were met. Neuropathy progressed rapidly over the next four weeks, rendering the patient nearly wheelchair bound by time of treatment commencement.
Discussion This case highlights that in POEMS syndrome: serum paraprotein is sometimes undetectable, thrombotic complications are common, and neuropathy can sometimes present subacutely and progress rapidly.
