Delay in BPDCN diagnosis can be deadly—include CD123, CD4, and CD56 in every hematologic diagnostic panel1,2*

Cell surface markers: vital to navigating hematologic cancer diagnosis

Cell surface markers are a critical diagnostic factor in identifying cancers, including hematologic malignancies.

While these markers may overlap among different cancers, unique combinations can identify a cancer and offer potential therapeutic targets. Once uncovered, they contribute to a more precise and rapid diagnosis.1,3

  • BPDCN may be suspected from clinical presentation and histological findings, but the final diagnosis relies on a compatible immunophenotype1
  • Immunophenotypes can be identified via immunohistochemistry or flow cytometry1
  • The CD123 marker is expressed by a number of hematologic cancers, including BPDCN4,5

Diagnosis of BPDCN depends on the identification of certain marker proteins, including CD1231

CD123 is a rapidly emerging therapeutic target in hematologic cancer1,6

CD123, as part of a signature marker triad with CD4 and CD56, is a key marker in identifying BPDCN—an often underrecognized and misdiagnosed disease.1,2,6*

While CD4 and CD56 are often standard markers for many hematologic diagnostic panels, historically CD123 has not consistently been included in early hematologic panels.7,8

Adding CD123 to initial hematologic panels is important for an accurate diagnosis of BPDCN.1,5

Key features of CD123 expression:

  • Highly expressed on BPDCN cells (~95%) and negligibly expressed on healthy cells4,5,9,10
  • Can be identified through any biopsy of malignant cells5
  • Can be both a diagnostic marker and a therapeutic target in BPDCN4-6

*BPDCN can include other markers, such as TCL1, TCF4, and CD303 (BDCA2).1,12

BPDCN can be identified by any biopsy of malignant cells5

Skin

Punch biopsy of a skin lesion showing BPDCN (H & E stain, ×40) and (inset) medium-sized malignant cells spare the epidermis (H & E stain, ×1000).11

Reprinted by permission of SAGE Publications, Inc.

Bone marrow

Bone marrow core biopsy showing diffuse infiltrate by BPDCN (H & E stain, ×600).11

Reprinted by permission of SAGE Publications, Inc.

Main morphologic features of BPDCN biopsy5:

  • Diffuse, monomorphic infiltrate
  • Medium-sized blast cells with irregular nuclei
  • Fine chromatin
  • At least 1 small nucleolus
  • Malignant BPDCN cells do not typically infiltrate the epidermis

Biopsies of the skin, bone marrow, or secondary sites are critical to BPDCN diagnosis5

BPDCN = blastic plasmacytoid dendritic cell neoplasm; H & E = hematoxylin and eosin.

References: 1. Pagano L, et al. Blastic plasmacytoid dendritic cell neoplasm: diagnostic criteria and therapeutical approaches. Br J Haematol. 2016;174(2):188-202. 2. Pemmaraju N, Konopleva M. Treating blastic plasmacytoid dendritic cell neoplasm. The Hematologist website. http://www.hematology.org/Thehematologist/Ask/8927.aspx. Published August 28, 2018. Accessed February 5, 2020. 3. Reichard KK. Blastic plasmacytoid dendritic cell neoplasm: how do you distinguish it from acute myeloid leukemia? Surg Pathol Clin. 2013;6(4):743-747. 4. Laribi K, et al. Blastic plasmacytoid dendritic cell neoplasm: from origin of the cell to targeted therapies. Biol Blood Marrow Transplant. 2016;22(8):1357-1367. 5. Facchetti F, et al. Neoplasms derived from plasmacytoid dendritic cells. Mod Pathol. 2016;29(2):98-111. 6. Pemmaraju N. Novel pathways and potential therapeutic strategies for blastic plasmacytoid dendritic cell neoplasm (BPDCN): CD123 and beyond. Curr Hematol Malig Rep. 2017;12(6):510-512. 7. Safaei A, et al. Blastic plasmacytoid dendritic cell neoplasm; a report of three cases. Iran J Med Sci. 2019;44(1):74-78. 8. Julia F, et al. Blastic plasmacytoid dendritic cell neoplasm: clinical features in 90 patients. Br J Dermatol. 2013;169(3):579-586. 9. Pagano L, et al. Blastic plasmacytoid dendritic cell neoplasm with leukemic presentation: an Italian multicenter study. Haematologica. 2013;98(2):239-246. 10. Frankel AE, et al. Activity of SL-401, a targeted therapy directed to interleukin-3 receptor, in blastic plasmacytoid dendritic cell neoplasm patients. Blood. 2014;124(3):385-392. 11. Riaz W, et al. Blastic plasmacytoid dendritic cell neoplasm: update on molecular biology, diagnosis, and therapy. Cancer Control. 2014;21(4):279-289. 12. Ceribelli M, Hou ZE, Kelly PN, et al. A druggable TCF4- and BRD4-dependent transcriptional network sustains malignancy in blastic plasmacytoid dendritic cell neoplasm. Cancer Cell. 2016;30(5):764-778.