Joseph Susa, Dermatopathologist at Propath and Global Pathology Laboratory, shared a post on X:
“For years Blastic Plasmacytoid Dendritic Cell Neoplasm (BPCDN) was taught to dermatology and pathology residents with the mnemonic CD123456; referencing the common immunophenotype CD 123 + CD4 + CD 56, but the diagnostic criteria were updated by the WHO in 2022. Here’s the new criteria:
(Table from: Lee YJ, Kim Y, Park SH, Jo J. Plasmacytoid dendritic cell neoplasms. BR 2023;58:S90-S95.)
So in basic text you need: Appropriate morphology and phenotype of CD123 plus either CD4 or 56; Plusa one of the plasmacytoid dendritic cell markers TCF4, TCL1, CD303, or CD304. That would lock the diagnosis! Or Any three PDC markers and absence of all expected negative markers.
This post is in response to the FDA approval yesterday of Abbvie’s new antibody conjugated drug (ADC) pivekimab sunirine-pvzy, which is an Anti-CD123 targeted chemotherapy for BPCDN. Seemed like a good time to review the diagnostic criteria.
If you write ‘check margin’ on your DIF specimen. I’m sorry, my brain turns off. You are not a serious person.”
Title: Plasmacytoid dendritic cell neoplasms
Authors: Yoo Jin Lee, Youjin Kim, Sang Hyuk Park, Jae-Cheol Jo
Other articles about FDA Approvals on OncoDaily.