MGUS bone

A 65-year-old man was referred to our hospital to undergo orthopedic surgery due to severe cervical ossification of the posterior longitudinal ligament. Computed tomography scanning showed a massive osteolytic lesion in his pelvis. Other screening examinations including detection of bone mineral density and osteoporosis biomarkers, bone scintigram and (18)F-fluorodeoxyglucose-positron emission tomography were all normal. Bone marrow aspiration revealed slightly increased plasmacytes at 3.8%. These findings led to a diagnosis of monoclonal gammopathy with undetermined significance (MGUS). Architectural osteolytic bone associated with MGUS without apparent abnormality in bone mineral metabolism could be a common occurrence prior to onset or occurrence of multiple myeloma.