Blastic Plasmacytoid Dendritic Cell Neoplasm

Blastic Plasmacytoid Dendritic Cell Neoplasm

Aaron Auerbach, MD, PhD

This patient rapidly developed generalized, indurated, purplish-red, well-defined papules and coalescent plaques over his legs. (Courtesy J. Alonso, MD.)

BPDCN shows the dermis replaced by a diffuse infiltrate of tumor cells with an infiltrative pattern, dissecting between collagen bundles image. The epidermis is spared, with a grenz zone image. (Courtesy L. J. Medeiros, MD.)



  • Blastic plasmacytoid dendritic cell neoplasm (BPDCN)

    • Terminology in 4th edition of World Health Organization classification


  • CD4(+)/CD56(+) hematodermic neoplasm

  • CD4(+)/CD56(+) blastic tumor of skin

  • Blastic NK-cell lymphoma

  • Agranular CD4(+) natural killer cell leukemia


  • Aggressive tumor of precursor plasmacytoid dendritic cells, which usually involves the skin; frequently culminates in leukemia

    • Included in the T-cell/NK-cell neoplasm section of the WHO classification, even though it is a tumor of plasmacytoid dendritic cells


Plasmacytoid Dendritic Cells (PDCs)

  • PDCs are found in T-cell areas of hematopoietic tissue

    • Found in lymph node, bone marrow, blood, and spleen (subcapsular)

      • Enter lymph node and mucosa in response to immune activation

  • Functions of plasmacytoid dendritic cells

    • Interferon-γ production

    • IL-3α expression

    • Dendritic cell differentiation following exposure to IL3 and CD40

  • Immunophenotype of plasmacytoid dendritic cells

    • Positive for

      • CD4, CD123, BDCA-2, CLA, TCL1, HLA-DR, CD43, CD68

    • Negative for

      • CD56, TdT, TIA-1, perforin

  • Diseases with ↑ plasmacytoid dendritic cells

    • Castleman lymphadenopathy

    • Kikuchi-Fujimoto disease

    • Classic Hodgkin lymphoma

    • Chronic granulomatous inflammation

    • Psoriasis

    • Lupus erythematosus



  • Incidence

    • Rare

      • < 1% of all acute leukemias

      • < 1% of cutaneous lymphomas

  • Age

    • Usually middle age to elderly

      • Can occur in children

    • Median: 65 years

      • Range: 8-96 years

  • Gender

    • M:F = 3.3:1.0

  • Ethnicity

    • No association


  • Often presents in > 1 anatomic site

    • Skin

      • Most common 1st manifestation of disease

      • Eventually skin involvement in nearly all patients

      • 50% confined to skin at initial staging

    • Bone marrow and peripheral blood

      • 60-90% of cases

      • There are rare leukemia variants without skin involvement that are recognized with intensive immunophenotyping

      • Can be subtle infiltrates in bone marrow

    • Lymph node

      • 45% of cases

  • Other organs that have been reported to be involved by BPDCN

    • Liver, spleen, tonsils, nasopharynx, conjunctiva, kidneys, central nervous system


  • Generalized, localized, or solitary cutaneous lesions

    • Macules, plaques, &/or tumors

      • Sometimes erythema &/or purpura

  • Lymphadenopathy

  • Rarely B symptoms present

Laboratory Tests

  • Cytopenias

    • Thrombocytopenia most common

  • Monocytosis is sometimes present

Natural History

  • Relapse and metastasis in most cases

    • Soft tissue and CNS frequently at relapse, but rare at diagnosis

  • Leukemia

    • Often relapses as leukemia

      • 10-20% of cases develop into acute myeloid leukemia

      • Often myelomonocytic leukemia

    • Presents more like leukemia than lymphoma


  • Adjuvant therapy

    • Multiagent chemotherapy

      • Poor response to non-Hodgkin lymphoma chemotherapy (R-CHOP)

      • 90% of cases relapse after chemotherapy

    • Acute lymphoblastic leukemia protocols

      • Intrathecal chemotherapy followed by allogeneic bone marrow transplantation

      • Most effective therapy, especially in children


  • Poor

    • Median survival ˜ 13 months

      • Less aggressive in children with median survival of 3 years

      • Often favorable initial response to chemotherapy, but eventual relapse


General Features

  • Nodules, tumors, or plaques of skin, which may have ulceration


Histologic Features

  • Skin

    • Dermal infiltrate

      • Typically extends into subcutaneous tissue

      • Spares the epidermis with grenz zone

    • Growth pattern

      • Diffuse, if extensive involvement

      • Perivascular

      • Periadnexal

    • Increased mitotic figures

    • Extravasated erythrocytes

    • Scattered reactive T cells amidst tumor cells

  • Lymph node

    • Effacement of lymph node architecture

      • Often interfollicular and medullary involvement by tumor

      • Sometimes tumor in sinuses

  • Bone marrow

    • Aggregates of tumor cells or scattered tumor cells

      • Often interstitial distribution

    • Residual bone marrow often shows dysplasia

  • Peripheral blood

    • Tumor cells can have vacuoles in the cytoplasm

      • Pseudopods

      • Resemble monoblasts

Cytologic Features

  • Medium-/large-sized atypical cells

    • Usually fine blastic chromatin, resembling lymphoblast or myeloblast

      • 1 or more small nucleoli

    • Sometimes tumor cells have more atypia and coarse chromatin

    • Sparse cytoplasm



  • MPO

    • Reactivity: Negative

    • Staining pattern

      • Cytoplasmic

  • NSE

    • Reactivity: Negative

    • Staining pattern

      • Cytoplasmic


Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Blastic Plasmacytoid Dendritic Cell Neoplasm

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