T-cell prolymphocytic leukemia: Difference between revisions
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==Clinical Features== |
==Clinical Features== |
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==Etiology== |
===Etiology=== |
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It is postulated that the originating cell line for this disease is a mature (post-thymic) T-cell.<ref name="who1"/> |
It is postulated that the originating cell line for this disease is a mature (post-thymic) T-cell.<ref name="who1"/> |
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Revision as of 21:12, 19 April 2007
Introduction
Synonyms
T-cell-prolymphocytic leukemia/T-cell chronic lymphocytic leukemia, "Knobby" type of T-cell leukemia, T-prolymphocytic leukemia/T-cell lymphocytic leukemia[1]
ICD-O Code
9834/3[1]
Definition
T-cell prolymphocytic leukemia (T-PLL) is a mature T-cell leukemia with aggressive behavior and predilection for blood, bone marrow, lymph nodes, liver, spleen, and skin involvement.[1]
Epidemiology
T-PLL is a rare leukemia, primarily affecting adults over the age of 30. It represents 2% of all small lymphocytic leukemias in adults.[2]
Clinical Features
Etiology
It is postulated that the originating cell line for this disease is a mature (post-thymic) T-cell.[1]
Clinical Presentation
Patients typically have systemic disease at presentation, including hepatosplenomegaly, generalized lymphadenopathy, and skin infiltrates.[1]
Laboratory Findings
A high lymphocyte count (> 100 x 109/L)along with anemia and thrombocytopenia are common findings. HTLV-1 serologies are negative, and serum immunoglobins are within normal limits with no paraproteins present.[1]
Sites of Involvement
Due to the systemic nature of this disease, leukemic cells can be found in peripheral blood, lymph nodes, bone marrow, spleen, liver, skin.[1]
Morphology
Peripheral blood and bone marrow
In the peripheral blood, T-PLL consists of medium-sized lymphocytes with single nucleoli and basophilic cytoplasm with occasional blebs or projections. The nuclei are usually round to oval in shape, with occasional patients having cells with a more irregular nuclear outline that is similar to the cerebriform nuclear shape seen in Sézary syndrome.[3] Marrow involvement is typically diffuse with morphology similar to what is observed in peripheral blood.[1]
Other sites
In the spleen, the leukemic cell infiltrate both the red pulp and white pulp, and lymph node involvement is typically diffuse through the paracortex.[1]. Skin infiltrates are seen in 20% of patients, and the infiltrates are usually dense and confined to the dermis and around the skin appendages.[2]
Variant morphology
A small cell variant comprises 20% of all T-PLL cases, and the Sézary cell-like (cerebriform) variant is seen in 5% of cases.[3]
Molecular Findings
Immunophenotype
T-PLL has the immunophenotype of a mature (post-thymic) T-lymphocyte, and the neoplastic cells are typically positive for pan-T antigens CD2, CD3, and CD7 and negative for TdT and CD1a. The immunophenotype CD4+/CD8- is present in 60% of cases, the CD4+/CD8+ immunophenotype is present in 25%, and the CD4-/CD8+ immunophenotype is present in 15% of cases.[2]
Genetic Findings
Clonal TCR gene rearrangements for the γ and δ chains are typically found. The most frequent chromosomal abnormality is the inversion of chromosome 14, specifcally inv 14(q11;q32). This is found in 80% of cases, while 10% of cases show a reciprocal translocation of chromosome 14 (t(14;14)(q11;q32)). [4][5] Also, abnormalities of chromosome 8 are seen approximately 75% of patients, including idic (8p11), t(8;8)(p11-12;q12), and trisomy 8.[6]
Current Articles
References
- ^ a b c d e f g h i [1] Jaffe E.S., Harris N.L., Stein H., Vardiman J.W. (eds): World Health Organization Classification of Tumors. Pathology and Genetics of Tumours of Haemopoietic and Lymphoid Tissues. IARC Press: Lyon 2001
- ^ a b c [2] E Matutes, V Brito-Babapulle, J Swansbury, J Ellis, R Morilla, C Dearden, A Sempere, and D Catovsky. "Clinical and laboratory features of 78 cases of T-prolymphocytic leukemia.", Blood, Dec 1991; 78: 3269 - 3274. PMID: 1742486
- ^ a b [3] Matutes E, Garcia Talavera J, O'Brien M, Catovsky D. "The morphological spectrum of T-prolymphocytic leukaemia.", Br J Haematol. 1986 Sep;64(1):111-24. PMID: 3489482
- ^ [4] Brito-Babapulle V and Catovsky D. "Inversions and tandem translocations involving chromosome 14q11 and 14q32 in T-prolymphocytic leukemia and T-cell leukemias in patients with ataxia telangiectasia." Cancer Genet Cytogenet. 1991 Aug;55(1):1-9. PMID: 1913594
- ^ [5] Maljaei SH, Brito-Babapulle V, Hiorns LR, Catovsky D. "Abnormalities of chromosomes 8, 11, 14, and X in T-prolymphocytic leukemia studied by fluorescence in situ hybridization." Cancer Genet Cytogenet. 1998 Jun;103(2):110-6. PMID: 9614908
- ^ [6] Sorour A, Brito-Babapulle V, Smedley D, Yuille M, Catovsky D. "Unusual breakpoint distribution of 8p abnormalities in T-prolymphocytic leukemia: a study with YACS mapping to 8p11-p12." Cancer Genet Cytogenet. 2000 Sep;121(2):128-32. PMID: 11063795