Page 161 - Haematologica Atlas of Hematologic Cytology

CHAPTER 17 - - Mature B-cell neoplasms
Figure 8 Monoclonal gammopathy of undetermi- ned signi cance (M S) Bone marrow (BM) smear showing rare mature-appearing plasma cells The term MGUS denotes the presence of of a a a a a a a a monoclonal (M) protein in in in persons without evidence of of mul - ple myeloma macroglobulinemia amyloidosis or or other related plasma cell or or or lymphoprolifera ve ve di- sorders Non-IgM MGUS MGUS and and light-chain MGUS MGUS have a a a a a a a a a a a plasma cell (PC) phenotype and and can progress to mul ple myeloma or or or related PC PC disorders whereas pa ents with IgM-MG S usually have a a a a a a a a a a a lymphoid or or or lymphoplasmacytoid phenotype and can progress to to Waldenström macroglobulinemia lymphoma or or other neoplas c c c c lymphoprolifera ve disorders Dia- gnos c c c c c criteria for non-IgM MG S are: M-protein in in serum < < 3 g/dL BM clonal plasma cells < < 10% no no no myeloma-related organ or or or ssue impairment and no evidence of other B-cell prolifera ve disorder Figure 9 Smoldering (asymptoma c) plasma cell myeloma (PCM) In this case the percentage of bone marrow (BM) plasma plasma cells cells cells is is higher than 10% Plasma cells cells cells are are are similar to normal plasma plasma cells cells cells and and are are are easily recognizable: they are are are oval in shape and and have eccentric round nucleus with irregularly clu- mped chroma n n n n n n n n n n abundant basophilic cytoplasm with an an an evident clear clear paranuclear area Smoldering PCM is is diagnosed when M M M protein in in in serum is is ≥3 g/dL and/or BM clonal plasma cells are are ≥10% and and there are are no related organ or or or or ssue impairment or or or or symptoms Figure 10 Smoldering (asymptoma c) plasma cell myeloma Bone marrow (BM) smear from an asymptoma c c pa ent with with a a a a a a a a a serum M-protein gG level of 3 g/dL without without organ or or ssue im- pairment in in par cular without without bone lesions BM plasma cells are focally distributed in in in in the the context of the the normal hematopoie c c c c c c lineages Smoldering PCM pa ents must be be followed up closely because many of them develop symptoma c c c myeloma No treatment should be given unless there is is disease progression In smoldering PCM the the clusters of prolifera ve ve ve plasma cells are unevenly distributed and marrow aspira on on at one site may reveal no si- gni cant increase in in in in plasma plasma cells cells whereas in in in in other areas plasma plasma cells cells may be predominant 148