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T-cell prolymphocytic leukemia



T-cell-prolymphocytic leukemia
Classification & external resources
ICD-O: 9834/3

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] 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] Other names include: T-cell chronic lymphocytic leukemia, "Knobby" type of T-cell leukemia, T-prolymphocytic leukemia/T-cell lymphocytic leukemia[1]

Additional recommended knowledge

Contents

Clinical Features

Due to the systemic nature of this disease, leukemic cells can be found in peripheral blood, lymph nodes, bone marrow, spleen, liver, skin.[1]

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]

Morphology

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]

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]

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. ^ a b c d e f g h 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
  2. ^ a b c Matutes E, Brito-Babapulle V, Swansbury J, et al (1991). "Clinical and laboratory features of 78 cases of T-prolymphocytic leukemia". Blood 78 (12): 3269-74. PMID 1742486.
  3. ^ a b 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "T-cell_prolymphocytic_leukemia". A list of authors is available in Wikipedia.
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