TCL1 expression in plasmacytoid dendritic cells (DC2s) and the related CD4+ CD56+ blastic tumors of skin

• Published in: Blood 2003-06, Vol.101 (12), p.5007-5009
• Main Authors: Herling, Marco, Teitell, Michael A., Shen, Rhine R., Medeiros, L. Jeffrey, Jones, Dan
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Bone Marrow - chemistry; Bone Marrow - immunology; Bone Marrow - pathology; CD4 Antigens - analysis; CD56 Antigen - analysis; Dendritic Cells - chemistry; Dermatology; Hematopoietic Stem Cells - chemistry; Hematopoietic Stem Cells - immunology; Humans; Immunohistochemistry; Immunophenotyping; Interleukin-3 Receptor alpha Subunit; Killer Cells, Natural; Leukemia, Myeloid - metabolism; Leukemia, Myelomonocytic, Acute - pathology; Leukemia, Prolymphocytic - metabolism; Leukemia, T-Cell - metabolism; Lymph Nodes - immunology; Lymph Nodes - pathology; Lymphoma - chemistry; Lymphoma, T-Cell - chemistry; Medical sciences; Plasma Cells - chemistry; Plasma Cells - immunology; Protein-Serine-Threonine Kinases; Proto-Oncogene Proteins - analysis; Proto-Oncogene Proteins c-akt; Receptors, Interleukin-3 - analysis; Skin Neoplasms - chemistry; Skin Neoplasms - immunology; Tumors of the skin and soft tissue. Premalignant lesions
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2002-10-3297

Initially considered to be of natural killer (NK)–cell origin, CD4+ CD56+ blastic tumors (BTs) of skin have recently been proposed to be of dendritic cell lineage. We have previously described BTs with transformation to myelomonocytic leukemia. Here we report expression of the lymphoid proto-oncogene TCL1 in 10 (83%) of 12 BTs and in lymph node plasmacytoid dendritic cells (DC2s). TCL1 was also expressed in myelomonocytic blasts of 3 transformed BT cases but not in true NK-cell tumors (n = 18), de novo acute myelomonocytic leukemias (1 of 14, 7%), or mature T-cell malignancies (1 of 112, < 1%), with the exception of T-prolymphocytic leukemia (T-PLL). All BT cases were also positive for the DC2-associated marker CD123. These results further support derivation of BTs from DC2s, and demonstrate that TCL1 expression in this tumor is common to the immature blastoid, lymphoid-appearing, and subsequent myelomonocytic phases of this disease.