TCL-1 by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test info

TCL-1 by IHC
12376 - Technical only, 12379 - Technical & interpretation
  • All IHC stains will include a positive control tissue
  • TCL1 identifies blastic plasmacytoid dendritic cell neoplasm (BPDCN), which is a rare, highly malignant tumor with strong cutaneous tropism (nearly 100%) and leukemic phase either present at initial diagnosis (approximately 50% of cases) or in the subsequent course of the disease. Approximately 10-20% of cases are associated with or develop into AML
  • TCL1 should be used in an antibody panel to detect BPDCN, which are CD4+, CD56+, CD123+ and TCL1+. CD68 is positive in approximately 50% of cases (often cytoplasmic dot staining). TdT is positive in approximately 20-60% of cases. Suspected cases of BPDCN should be subjected to rigorous immunophenotyping (including MPO and flow cytometry, if available), to assess for acute leukemia
  • When only CD4, CD56 and CD123 are positive and TCL1 is negative, AML should be strongly considered
  • Tumors that share some but not all immunophenotypic features of BPDCN are better classified as "acute leukemia of ambiguous lineage"
  • TCL1 is also positive in most cases (75%) of T-PLL



Submit a formalin-fixed, paraffin embedded tissue block


Formalin-fixed, paraffin embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

  • Unlabeled/mislabeled block
  • Insufficient tissue
  • Slides broken beyond repair


AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination

Clinical and Interpretive info


If requested, an interpretive report will be provided



  • TCL1 (T-cell leukemia/lymphoma protein 1A) was originally identified in association with T-cell prolymphocytic leukemia (T-PLL). TCL1 reacts with human TCL1, which is involved with AKT phosphorylation/activation and is thought to enhance cell proliferation, stabilize mitochondrial membrane potential and promote cell survival
  • TCL1 is normally expressed in immature cortical thymocytes, activated peripheral T-cells, pro-B cells, and naïve mantle zone B-cells of peripheral lymphoid tissues, but not in post-germinal center B-cells and plasma cells

 Staining pattern

  • Nuclear and cytoplasmic staining


  1. WHO (2008) classification of tumors of hematopoietic and lymphoid tissues, p145-147.
  2. Am J Surg Pathol 2014;38:673-680


88342 - 1st stain
88341 - each additional stain