{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T02:05:43Z","timestamp":1784081143514,"version":"3.55.0"},"reference-count":15,"publisher":"The Korean Society of Pathologists and The Korean Society for Cytopathology","issue":"4","license":[{"start":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T00:00:00Z","timestamp":1776816000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["jpatholtm.org"],"crossmark-restriction":true},"short-container-title":["J Pathol Transl Med"],"published-print":{"date-parts":[[2026,7,15]]},"abstract":"<jats:p>CD138-negative plasma cell myeloma harboring a BRAF G469R mutation is described in a 76-year-old male presenting with multiple osteolytic lesions. Histologically, the lesion exhibited epithelioid to plasmacytoid morphology with prominent mitotic activity and vascular-like spaces. Immunophenotyping demonstrated strong vimentin and CD31 expression but absence of CD138 and other endothelial markers. Light-chain in situ hybridization confirmed a clonal \u03ba-restricted plasma cell population. Bone marrow examination revealed near-complete replacement by atypical plasma cells, retaining CD138 negativity and demonstrating focal CD20 positivity, indicative of intratumoral heterogeneity. Next-generation sequencing identified a rare BRAF G469R variant. The patient exhibited poor response to bortezomib, lenalidomide, and dexamethasone therapy, necessitating a switch to carfilzomib-based treatment. This case underscores the diagnostic challenges of CD138-negative myeloma and highlights the importance of integrating morphology, immunophenotyping, and molecular profiling to inform accurate diagnosis and guide therapeutic strategies.<\/jats:p>","DOI":"10.4132\/jptm.2026.02.02","type":"journal-article","created":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T01:40:23Z","timestamp":1776822023000},"page":"451-455","update-policy":"https:\/\/doi.org\/10.4132\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Phenotypic plasticity in plasma cell myeloma: a CD138-negative case with a rare BRAF G469R mutation"],"prefix":"10.4132","volume":"60","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6013-8579","authenticated-orcid":true,"given":"Sun-Ju","family":"Oh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0689-0270","authenticated-orcid":true,"given":"So-Hak","family":"Chung","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2611","reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2009-07-234757"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1007\/s10585-007-9125-3"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1136\/bcr-2019-232233"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1038\/leu.2012.80"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1038\/leu.2011.373"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2003-09-3064"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.3892\/ijo.2012.1545"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.3892\/ijo.2013.2134"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbamcr.2014.11.019"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1038\/s41388-018-0171-x"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.3390\/genes11111342"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.18632\/oncotarget.4434"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.1161\/circresaha.110.218396"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1016\/j.anndiagpath.2013.08.003"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1038\/leu.2016.77"}],"container-title":["Journal of Pathology and Translational Medicine"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/jpatholtm.org\/upload\/pdf\/jptm-2026-02-02.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/jpatholtm.org\/journal\/view.php?doi=10.4132\/jptm.2026.02.02","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/jpatholtm.org\/upload\/pdf\/jptm-2026-02-02.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T01:58:37Z","timestamp":1784080717000},"score":1,"resource":{"primary":{"URL":"http:\/\/jpatholtm.org\/journal\/view.php?doi=10.4132\/jptm.2026.02.02"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,15]]},"references-count":15,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2026,7]]}},"URL":"https:\/\/doi.org\/10.4132\/jptm.2026.02.02","relation":{},"ISSN":["2383-7837","2383-7845"],"issn-type":[{"value":"2383-7837","type":"print"},{"value":"2383-7845","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,15]]},"assertion":[{"value":"2025-11-21","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-02-02","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-04-22","order":2,"name":"published","label":"Published online","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-15","order":3,"name":"published","label":"Print publication","group":{"name":"publication_history","label":"Publication History"}}]}}