Vertebral lesion distribution in multiple myeloma--assessed by reduced-dose whole-body MDCT

To observe the distribution and potential distribution patterns of osteolytic and sclerotic vertebral involvement in a representative collective of multiple myeloma patients.

A total of 66 consecutive patients with a diagnosis of multiple myeloma at initial diagnosis or during follow-up were examined by multidetector reduced-dose computed tomography to evaluate the distribution of bone lesions along the spine with focus on size, location, and lesion character. Confirmation of diagnosis was performed by comparison to follow-up computed tomography or magnetic resonance tomography. If >50% of all detected malignant lesions occurred in one spinal segment, the distribution pattern was called cervical, thoracic, lumbar, or sacral, otherwise a "mixed" pattern was classified.

Of a total number of 933 osseous spine lesions, 632 (67.7%) were classified as malignant (98.9% of them osteolytic) and 293 (31.5%) as benign. The distribution pattern analysis yielded two patients (3.8%) with a cervical, 26 (50%) with a thoracic, 4 (7.7%) with a lumbar, one (1.9%) with a sacral pattern, and 19 cases (36.6%) showed a mixed distribution pattern. Segment-wise, the mean lesion size was 6.52 ± 2.76 mm (cervical), 8.97 ± 5.43 mm (thoracic), 11.97 ± 7.11 mm (lumbar), and 17.5 ± 16.465 (sacral), whilst, related to the vertebra size, the lesion/vertebra size ratio is decreasing through the whole spine beginning from the top.

Multiple myeloma bone lesions occur preferably and are larger in the thoracic and lumbar spine. Moreover, a specific distribution pattern is present in about 60%.