Hyperattenuating bone marrow abnormalities in myeloma patients using whole-body non-enhanced low-dose MDCT: Correlation with haematological parameters

We aimed to establish the role of hyperattenuating medullary abnormalities detected by whole-body non-enhanced low-dose multidetector CT (WBLD-MDCT) in multiple myeloma (MM) patients referred for primary evaluation. 50 consecutive patients with untreated Stage I (n_I=11). Stage II (n_II=10) and Stage III (n_III=29) MM underwent WBLD-MDCT for staging. The number and size of osteolysis, as well as haematologic parameters including paraprotein and β2-microglobulin levels, were assessed and related to the number, size and density of medullary abnormalities assumed to represent myeloma involvement. Bone marrow abnormalities were found in 2/11 (18%) Stage I, 6/10 (60%) Stage II and 20/29 (69%) Stage III myeloma patients, and did not parallel the incidence of osteolysis. Patients with medullary lesions had higher levels of immunoglobulin A (median, 4730 mg dl^-1 vs 1520 mg dl ^-1), light-chain proteinuria (median, 690 mg dl^-1 vs 214 mg dl^-1) and IgG paraprotein (median, 3270 mg dl^-1 vs 2610 mg dl^-1) compared with patients without medullary lesions. In patients with medullary abnormalities, levels of serum β2-microglobulin were significantly higher than in patients without detectable marrow infiltrates (median, 4.3 mg dl^-1 vs 2.4 mg dl^-1; p=0.0015). In conclusion, medullary abnormalities visualized by WBLD-MDCT are encountered in all stages of myeloma, including cases without osteolysis. They are associated with significantly elevated serum levels of paraprotein (reflecting tumour mass) and β2-microglobulin, a prospective prognostic marker for myeloma. The nature and possible prognostic significance of medullary abnormalities detected by WBLD-MDCT therefore warrants further investigation.