Search Database ICD-O-3 Code Lists

Name

Prolymphocytic leukemia, B-cell type (BLL) [OBS] (for 2026+, see 9823/3)

ICD-O-3 Morphology

9833/3: B-cell prolymphocytic leukemia
Effective 2001 - 2025

Reportable

for cases diagnosed 1978 - 2025

Primary Site(s)

C421
Primary site must be bone marrow (C421)

Coding Manual: Hematopoietic Coding Manual (PDF)

Abstractor Notes

Prolymphocytic leukemia, B-cell type (BLL) is part of the Mature B-cell neoplasms lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B15)

See 9823/3 for diagnosis of "prolymphocytic progression of CLL/SLL."

This neoplasm affects the peripheral blood (PB), bone marrow (BM) and spleen. Prolymphocytes must exceed 55% of lymphoid cells in PB. The leukemic cells are found in the PB, BM and spleen.

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

None

Definition

B-cell prolymphocytic leukemia (B-PLL) is a neoplasm of B-cell prolymphocytes affecting the peripheral blood, bone marrow, and spleen. Prolymphocytes must constitute > 55% of lymphoid cells in peripheral blood.

Per the WHO 5th edition, the definition of B-cell prolymphocytic leukemia is now classified as prolymphocytic progression of CLL/SLL and coded as 9823/3. This change takes place for cases diagnosed 1/1/26.

A diagnosis of "prolymphocytic progression of CLL/SLL" prior to 2026 is coded as 9833/3.

Definitive Diagnostic Methods

Cytogenetics
Genetic testing
Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

IG genes clonally rearranged with unmutated IGH gene
IGHV3 and IGHV4

Immunophenotyping

CD5+ (expression/positive)
CD19+ (expression/positive)
CD20+ (expression/positive)
CD22+ (expression/positive)
CD23+ (expression/positive)
CD38+ (expression/positive)
CD79a+ (expression/positive)
CD79b+ (expression/positive)
CD200+ (expression/positive)
FMC7+ (expression/positive)
Strong surface IgM +/- IgD

Treatments

Chemotherapy
Hormone therapy
Radiation therapy

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)

C91.3 Prolymphocytic leukemia of B-cell type (effective October 01, 2015)

Signs and Symptoms

Anemia
Massive splenomegaly
Rapidly rising lymphocyte count
Thrombocytopenia

Diagnostic Exams

Blood chemistry studies
Bone marrow aspiration and biopsy
CT (CAT) scan
Cytogenetic analysis
Immunophenotyping
Peripheral blood smear

Progression and Transformation

None

Epidemiology and Mortality

Age: 65-69 years median age
Incidence: ~1% of lymphocytic leukemias
Sex: no male or female predominance
Survival: 30-50 months median survival

Sources

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

Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds):
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition)
IARC: Lyon 2017
Section: Mature B-cell neoplasms
Pages: 222-223
Glossary