T-cell prolymphocytic leukemia pathophysiology
|
T-cell prolymphocytic leukemia Microchapters |
|
Differentiating T-cell Prolymphocytic Leukemia from other Diseases |
|---|
|
Diagnosis |
|
Treatment |
|
Case Studies |
|
T-cell prolymphocytic leukemia pathophysiology On the Web |
|
American Roentgen Ray Society Images of T-cell prolymphocytic leukemia pathophysiology |
|
Directions to Hospitals Treating T-cell prolymphocytic leukemia |
|
Risk calculators and risk factors for T-cell prolymphocytic leukemia pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Pathphysiology
It is postulated that the originating cell line for this disease is a mature (post-thymic) T-cell. Due to the systemic nature of this disease, leukemic cells can be found in peripheral blood, lymph nodes, bone marrow, spleen, liver, skin.
Microscopic Pathology
Marrow involvement is typically diffuse with morphology similar to what is observed in peripheral blood.[1] 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]
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] 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]
References
- ↑ 1.0 1.1 Invalid
<ref>tag; no text was provided for refs namedwho1 - ↑ 2.0 2.1 Invalid
<ref>tag; no text was provided for refs namedmat1 - ↑ 3.0 3.1 Matutes E, Garcia Talavera J, O'Brien M, Catovsky D (1986). "The morphological spectrum of T-prolymphocytic leukaemia". Br. J. Haematol. 64 (1): 111–24. PMID 3489482.
- ↑ Brito-Babapulle V, Catovsky D (1991). "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. 55 (1): 1–9. PMID 1913594.
- ↑ Maljaei SH, Brito-Babapulle V, Hiorns LR, Catovsky D (1998). "Abnormalities of chromosomes 8, 11, 14, and X in T-prolymphocytic leukemia studied by fluorescence in situ hybridization". Cancer Genet. Cytogenet. 103 (2): 110–6. PMID 9614908.
- ↑ Sorour A, Brito-Babapulle V, Smedley D, Yuille M, Catovsky D (2000). "Unusual breakpoint distribution of 8p abnormalities in T-prolymphocytic leukemia: a study with YACS mapping to 8p11-p12". Cancer Genet. Cytogenet. 121 (2): 128–32. PMID 11063795.