@article{JanjetovicLohneisNogaietal.2021, author = {Janjetovic, Snjezana and Lohneis, Philipp and Nogai, Axel and Balci, Derya and Rasche, Leo and J{\"a}hne, Doris and Bokemeyer, Carsten and Schilling, Georgia and Blau, Igor Wolfgang and Schmidt-Hieber, Martin}, title = {Clinical and biological characteristics of medullary and extramedullary plasma cell dyscrasias}, series = {Biology}, volume = {10}, journal = {Biology}, number = {7}, issn = {2079-7737}, doi = {10.3390/biology10070629}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242592}, year = {2021}, abstract = {Background: Extramedullary plasma cell (PC) disorders may occur as extramedullary disease in multiple myeloma (MM-EMD) or as primary extramedullary plasmocytoma (pEMP)/solitary osseous plasmocytoma (SOP). In this study, we aimed to obtain insights into the molecular mechanisms of extramedullary spread of clonal PC. Methods: Clinical and biological characteristics of 87 patients with MM-EMD (n = 49), pEMP/SOP (n = 20) and classical MM (n = 18) were analyzed by using immunohistochemistry (CXCR4, CD31, CD44 and CD81 staining) and cytoplasmic immunoglobulin staining combined with fluorescence in situ hybridization (cIg-FISH). Results: High expression of CD44, a cell-surface glycoprotein involved in cell-cell interactions, was significantly enriched in MM-EMD (90\%) vs. pEMP/SOP (27\%) or classical MM (33\%) (p < 0.001). In addition, 1q21 amplification by clonal PC occurred at a similar frequency of MM-EMD (33\%), pEMP/SOP (57\%) and classical MM (44\%). Conversely, del(17p13), t(4;14) and t(14;16) were completely absent in pEMP/SOP. Besides this, 1q21 amplification was identified in 64\% of not paraskeletal samples from MM-EMD or pEMP compared to 9\% of SOP or paraskeletal MM-EMD/pEMP and 44\% of classical MM samples, respectively (p = 0.02). Conclusion: Expression of molecules involved in homing and cytogenetic aberrations differ between MM with or without EMD and pEMP/SOP.}, language = {en} }