OBJECTIVETo study the clinical and pathologic features of multiple myeloma(MM) with CCND1.

METHODSRetrospectively analyzed the clinical and pathologic profiles of 158 patients with MM from 2010 to 2013. The clinical and morphologic features of bone marrow aspiration, biopsy and immunophenotypic analysis which was carried out by flow cytometry and immunohistochemistry were analyzed in all patients with MM respectively. CCND1 translocation was studied by FISH method in all cases. Classical cytogenetic studies of bone marrow were performed in 24 cases whose CCND1 was positive.

RESULTSIn the 158 patients with MM, CCND1 was detected in 31 patients (19.6%）. In 31 patients, type IgA, IgD, IgG, IgM, light-chain only and nonsecretory MM were 4 cases,4 cases,11 cases,1 case, 6 cases and 5 cases respectively. A high incidence of CCND1 was observed in IgD and nonsecretory MM comparied with IgA and IgG respectively (P<0.05). but no statistical significance was reached between κ and λ type patients (P=0.627). The morphology of plasma cell in bone marrow biopsies were small Lymphocyte- Like 24 cases,mature plasma cell 6 cases and immature plasma cell 1 case. Immunophenotype of all 31 cases was CD38⁺CD138⁺CD19⁻CD45⁻, (CD56⁺ in 11 cases, CD20⁺ in 9 cases, CD117⁺ in 3 cases. MM with CCND1 showed a strong association with CD20 expression, the lack of CD56 expression. Immunohistochemistry showed positive for cyclinD1 in 22 cases.

CONCLUSIONA high incidence of CCND1 was detected in the IgD and nonsecretory MM, and correlated with Small Lymphocyte- Like, higher positive rate of CD20, cyclinD1 and the lack of CD56 expression. MM with CCND1 must be distinguished from LPL and other mature B cell lymphomas which have plasmacytoid differentiation.