Search Database ICD-O-3 Code Lists

Name

T-cell prolymphocytic leukemia (T-PLL)

ICD-O-3 Morphology

9834/3: T-cell prolymphocytic leukemia
Effective 2001 and later

Reportable

for cases diagnosed 1978 and later

Primary Site(s)

C421
Primary site must be bone marrow (C421)

Coding Manual: Hematopoietic Coding Manual (PDF)

Abstractor Notes

T-cell prolymphocytic leukemia (T-PLL) is part of the Mature T-cell and NK-cell neoplasms lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B20)

T-cell prolymphocytic leukemia (T-PLL) is an aggressive T-cell leukemia.

Peripheral blood, bone marrow, spleen, liver, lymph node, and (sometimes) skin and serosa involvement is observed.

Hepatosplenomegaly and generalized lymphadenopathy with only slightly enlarged lymph nodes are observed. Cutaneous involvement is seen in approximately 20% of cases, and malignant effusions are seen in approximately 15%.

Diagnostic Confirmation

This histology can be determined by positive histology (including peripheral blood) with or without genetics and/or immunophenotyping. Review the Definitive Diagnostic Methods, Immunophenotyping and Genetics Data sections below, and the instructions in the Hematopoietic Manual for further guidance on assigning Diagnostic confirmation.

Module Rule

None

Alternate Names

Prolymphocytic leukemia, T-cell type
T-cell chronic lymphocytic leukemia

Definition

T-prolymphocytic leukaemia (T-PLL) is a clonal proliferation of small to medium-sized prolymphocytes with a mature postthymic T-cell phenotype characterized by the juxtaposition of TCL1A or MTCP1 to a TR locus, most often the TRA/TRD locus. (WHO 5th edition)

Definitive Diagnostic Methods

Cytogenetics
Genetic testing
Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

inv(14)(q11q32)
t(14;14)(q11;q32)
TCL1a and TCL1B at 14q32.1

Immunophenotyping

CD1a- (no expression/negative)
CD2+ (expression/positive)
CD3+ (expression/positive)
CD4+ (expression/positive)
CD5+ (expression/positive)
CD7+ (expression/positive)
CD8- (no expression/negative)
CD52 usually depressed at high density, can be used as a target of therapy
TdT- (no expression/negative)

Treatments

Chemotherapy
Hematologic Transplant and/or Endocrine Procedures

Transformations to

There are no known transformations

Transformations from

There are no known transformations

Same Primaries

Corresponding ICD-10 Codes (Cause of Death codes only)

C91.3 Prolymphocytic Leukemia

Corresponding ICD-10-CM Codes (U.S. only)

C91.6 Prolymphocytic leukemia of T-cell type (effective October 01, 2015 - September 30, 2024)
C91.60 Prolymphocytic leukemia of T-cell type not having achieved remission (effective October 01, 2024)
C91.6 Prolymphocytic leukemia of T-cell type, in remission (effective October 01, 2024)
C91.6 Prolymphocytic leukemia of T-cell type, in relapse (effective October 01, 2024)

Signs and Symptoms

Anemia
Generalized lymphadenopathy
Hepatosplenomegaly
Serous effusions (mostly pleural)
Skin infiltration (20% of patients)
Thrombocytopenia

Diagnostic Exams

Blood chemistry studies
Bone marrow aspiration and biopsy
Cytogenetic analysis
Flow cytometry
Immunohistochemistry
Immunophenotyping
Peripheral blood smear

Progression and Transformation

None

Epidemiology and Mortality

Incidence: 2% of cases of mature lymphocytic leukemias
Age: 65 years median age (range 30-94)
Sex: M:F ratio 1.33:1
Survival: median survival time 22 months

Sources

WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Mature T-cell and NK-cell leukemias
Pages: Part B: 658-661

International Classification of Diseases for Oncology, 3rd edition (including revisions). Geneva: World Health Organization, 2001, 2011, 2020.
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: http://www.iacr.com.fr/index.php?option=com_content&view=category&layout=blog&id=100&Itemid=577

PDQ® Adult Treatment Editorial Board. PDQ Peripheral T-Cell Non-Hodgkin Lymphoma Treatment. Bethesda, MD: National Cancer Institute. Updated <03/13/2025>. Available at: https://www.cancer.gov/types/lymphoma/hp/peripheral-t-cell-lymphoma-pdq. Accessed <03/31/2025>. [PMID: 37437079]
Section: Peripheral T-Cell Non-Hodgkin Lymphoma Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/lymphoma/hp/peripheral-t-cell-lymphoma-pdq#_2289
Glossary