Sixty-six-year-old female presented with left forearm soft tissue swelling for 2 months. An ultrasound of her left forearm showed a 6.5 cm × 1 cm × 3.6 cm soft tissue mass, which was also confirmed by magnetic resonance imaging (Panel A and B). A routine screening mammogram revealed a new 4 mm mass in her left breast. Subsequent left breast needle biopsy and left forearm fine needle aspiration favored an undifferentiated malignant neoplasm of hematolymphoid origin (Panel D) with positive CD4 (Panel E) and positive CD56 (Panel F) markers compatible with blastic plasmacytoid dendritic cell neoplasm (BPDCN). Positron emission tomography (PET) scan showed increased uptake in the left forearm (Panel C), left breast, bilateral pleura, liver, spleen, portocaval lymph nodes, and omental caking. A bone marrow biopsy was negative for malignancy, and shortly thereafter the patient underwent induction therapy with cytarabine and idarubicin. Following progression of metastatic disease on PET scan, the patient received reinduction chemotherapy with mitoxantrone, etoposide, and cytarabine.

BPDCN is a rare malignancy formerly recognized as CD4+/CD56+ hematodermic neoplasm and is suggested to have derived from plasmacytoid dendritic cells. It typically presents in middle-aged or elderly patients with skin or soft tissue involvement and concurrent disseminating disease carrying poor prognosis. BPDCN expresses CD4, CD56, CD123 (interleukin-3 receptor alpha chain), and BDCA-2 (blood dendritic cell antigen 2), whereas expression of TCL1 is helpful when the tissue displays weak expression of aforementioned markers. Treatment involves multiagent chemotherapy followed by subsequent stem cell transplantation for best outcomes. Unfortunately, our patient showed dismal response to chemotherapy, and the originally intended stem cell transplantation could not be instituted due to poor performance status.

thumbnail image

Illustration Image 1.. Panel A and B, magnetic resonance imaging of left forearm mass. Panel C, positron emission tomography showing increased uptake in the left fore arm. Panel D, Hematoxylin-eosin stain. Panel E, positive CD4. Panel F, positive CD56.

Download figure to PowerPoint


  1. Top of page
  2. References
  • 1
    Lopez V,Marti N,Ferrandez A, et al. An atypical presentation of a blastic plasmacytoid dendritic cell tumors. J Cutan Pathol. 2010 Sep; 37(9): e502. Epub 2009 Jul 13.
  • 2
    Dalle S,Beylot-Barry M,Bagot M, et al. Blastic plasmacytoid dendritic cell neoplasm: is transplantation the treatment of choice? Br J Dermatol. 2010 Jan; 162(1): 749. Epub 2009 Jun 22.
  • 3
    Male HJ,Davis MB,Mcguirk JP, et al. Blastic plasmacytoid dendritic cell neoplasm should be treated with acute leukemia type induction chemotherapy and allogeneic stem cell transplantation in first remission. Int J Hematol. 2010 Sep; 92(2): 398400. Epub 2010 Aug 11.