Utility of hematology analyzer and flow cytometry in timely and correct detection of circulating plasma cells: Report of three cases

Abstract

CBC findings can prompt early suspicion of circulating PCs in PCM patients leading to early and accurate flow cytometric analysis of clonal PCs in addition to morphological PB evaluation. The suggested combined approach proved to be most important in the PCL case with discordant morphological evaluations and marginal PC numbers according to current criteria. © 2016 International Clinical Cytometry Society.

CD5+ B lymphoproliferative disorder with subsequent development of plasma cell leukaemia: Diagnostic and aetiologic reasoning

“…In PB, FC analysis, but not morphology, was able to detect abnormal PCs at a level above the diagnostic threshold for PCL, which in this case was at a marginal number (22.7% of nucleated, 2.8 3 10 9 /L), in addition to monotypic B lymphocytes, establishing the diagnosis of concurrent PCL according to current criteria (17). This observation supports our recent findings showing the importance of PB immunophenotyping in diagnosis of PCL (18). In addition, FC immunophenotyping of BM aspirate disclosed residual abnormal B cells with a comparable phenotype to the preexistent B LPD and the same light chain restriction with the neoplastic PCs.…”

Detection of Circulating Tumor Plasma Cells in Monoclonal Gammopathies: Methods, Pathogenic Role, and Clinical Implications

“…These counts already proved critical for the differential diagnosis between MM and PCL [ 18 , 110 ]. In addition, they confirmed the presence of variable PC counts in a minor fraction (17%) of all MM patients [ 30 ], which (frequently) cannot be accurately discriminated from normal/reactive plasmablasts [ 111 ] due to both the limited number of nucleated cells evaluated (i.e., <500 cells) and their morphological similarities [ 112 ], particularly among patients that show low numbers of circulating PC. Because of these limitations and the clear clinical utility of CTPC detection and quantitation in blood, conventional immunocytochemistry-based approaches were subsequently adopted.…”

Necessity of flow cytometry assessment of circulating plasma cells and its connection with clinical characteristics of primary and secondary plasma cell leukaemia

“…However, this favours FC as a complementary or even a primary diagnostic method in PCL that should be changed in diagnostic criteria. It is known that exact enumeration of cPCs by conventional cell count could be complicated by lower sensitivity; 30 on contrary, morphology assessment of PB smear by subjectivity 31 . Also, evaluation experience is needed as PCL with atypical and/or ambiguous morphology was documented as well 32 .…”

“…It seems that FC is an indispensable method for PCL diagnosis as well as for other PCDs 15,16,31,33 . Nowadays, standardisation of FC analyses by the Euroflow PCD protocol is available and recommended, not only for clinical studies 51 .…”

“…It is known that exact enumeration of cPCs by conventional cell count could be complicated by lower sensitivity; 30 on contrary, morphology assessment of PB smear by subjectivity. 31 Also, evaluation experience is needed as PCL with atypical and/or ambiguous morphology was documented as well. 32 FC, a progressively evolving method, allows clear identification of PCs and, thus, overcomes the limitations of morphology assessment mentioned above.…”