Multimodal imaging and clinical characteristics of bone lesions in POEMS syndrome

POEMS syndrome is a rare plasmacyte-associated disease, one of the major diagnostic criteria of which is sclerotic bone lesion. To detect bone lesions in POEMS syndrome, which imaging method should be routinely applied and what characteristics they display are still unconfirmed. We analyzed clinical data and imaging characteristics of bone lesions in 22 patients with POEMS using multimodal methods, including conventional X-ray, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography/computed tomography (PET/CT). Images on X-ray and CT exhibited plaque-like high-density for osteosclerotic lesions and punched-out low-density appearance for osteolytic ones. X-ray had advantage in detecting bone lesions in skull, extremity long bones, clavicle, and scapula, while CT could display sharp outline of lesions and was more sensitive than X-ray in detecting the small lesions. Osteosclerotic lesions on MRI demonstrated decreased signal intensity on both T1 and T2-weighted sequences, while osteolytic lesions or osteolytic part of mixed lesions showed high signal intensity on T2-weighted sequences. MRI had same sensitivity as CT, but with superiority in distinguishing the active osteolytic lesions from the osteosclerotic ones. PET-CT showed (18)F-FDG uptake was normal in the majority of osteosclerotic lesions, and slightly increased in mixed ones, but obviously elevated in osteolytic ones. PET/CT was less sensitive in detecting osteosclerotic lesions than in detecting osteolytic ones. In conclusion, to detect bone lesions in POEMS, conventional X-ray scan should be first performed, further followed by more sensitive CT or MRI. PET-CT is optional when the osteolytic lesions are suspected.