Lymphoma and plasma cell neoplasms
T / NK cell disorders
T cell prolymphocytic leukemia

Author: Dragos Luca, M.D. (see Authors page)

Revised: 23 March 2017, last major update August 2011

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: T cell prolymphocytic leukemia [title]

Cite this page: Lymphoma - Non B cell neoplasms - T cell prolymphocytic leukemia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphomanonBTcellpro.html. Accessed October 17th, 2017.
Definition / general
Terminology
  • Historically, small cell variants were termed T cell chronic lymphocytic leukemia
Epidemiology
  • Rare, 2% of mature lymphocytic leukemias in adults > 30 years of age
  • Median age 65 years; range: 30 - 94 years
Sites
  • Peripheral blood, bone marrow, lymph nodes, spleen, liver, skin
Clinical features
  • Presents with high WBC count (75% are > 100K) and cutaneous (20 - 27%) or mucosal disease
  • Lymphadenopathy (53%), hepatomegaly (40%), splenomegaly (73%), CNS involvement, anemia and thrombocytopenia, serous effusions (mostly pleural) (Am J Clin Pathol 2005;123:456)
  • Normal serum Ig, HTLV-I negative
Case reports
Prognosis and treatment
  • May initially be indolent but median survival is usually less than 1 year
  • Usually not curable but cases with a more chronic course have been reported (may show an accelerated course after 2 - 3 years)
  • Best treatment response with alemtuzumab (anti-CD52)
  • Poor prognostic factors: high expression of TCL1 and AKT1
Postulated normal counterpart
  • Unknown T cell with a mature (post-thymic) immunophenotype (possibly intermediate between cortical and mature T lymphocytes – weak surface CD3, strong CD7, double CD4 / CD8 positive)
Microscopic (histologic) description
Peripheral blood and bone marrow:
  • Small to medium sized lymphocytes with abundant basophilic, nongranular cytoplasm, atypical nucleus, prominent nucleolus
  • Small cell variant: small cells with indistinct nucleoli; 19 - 25% of cases
  • Cerebriform nuclei in 5% of cases
  • All variants: cytoplasmic protrusions or blebs
  • Diffuse BM infiltration

Other tissues:
  • Diffuse involvement of splenic red and white pulp (atrophied) with invasion of blood vessels and splenic capsule
  • Diffuse paracortical involvement of lymph nodes, sometimes with sparing of the follicles; increased and often infiltrated high endothelial venules
  • Skin involvement is usually perivascular or periadnexal, may be diffuse dermal, no epidermotropism
Microscopic (histologic) images

Images hosted on other servers:

Various images and review

Small cell variant

Peripheral blood (A&B)

Peripheral blood

Immunohistochemistry
Positive stains
  • CD2, CD3, CD5, CD7, CD4 (60%), CD52 (high density expression, potential therapeutical target), TCL1
  • CD4+ / CD8- in 60% of cases, CD4+ / CD8+ in 25%, CD4- / CD8+ in 15%
Negative stains
Molecular / cytogenetics description
  • T cell receptor gene rearrangements (TRB@ & TRG@)
  • 75 - 80% show inv 14(q11;q32) (affects T cell receptor) or other chromosome 14 translocations
  • Reciprocal tandem translocations of TCL1 gene at 14q32.1 [t(14;14)(q11;q32)] in 10% of cases
  • MTCP1 gene at Xq28 in t(X;14)(q28;q11) translocations less common
  • Chromosome 8 abnormalities in 70 - 80% of cases [idic 8p11, t(8;8)(p11-12;q12), trisomy 8q]
  • ATM gene at 11q23, 12p13-, chromosome 6 abnormalities (33%) and 17 (26%), TP53 deletions
Additional references