T-cell large granular lymphocytic leukemia

ICD-O-3 Morphology

9831/3: T-cell large granular lymphocytic leukemia
Effective 2010 and later


for cases diagnosed 2010 and later

Primary Site(s)

Primary site must be bone marrow (C421)


Not Applicable

Module Rule


Alternate Names

Chronic NK-cell lymphocytosis
Indolent large granular NK-cell lymphoproliferative disorder
Large granular lymphocytosis, NOS
NK-cell LGL lymphocytosis
NK-cell large granular lymphocytic leukemia
NK-cell lineage granular lymphocyte proliferative disorder
T-cell large granular lymphocytosis
T-cell lymphoproliferative disease of granular lymphocytes
T-gamma lymphoproliferative disease [OBS]


T-cell large granular lymphocytic leukemia (T-LGLL) is a heterogenuous disorder characterized by a persistent (> 6 months) increase in the number of peripheral blood large granular lymphocytes (LGLs) without a clearly identified cause.

Chronic lymphoproliferative disorder of NK cells (CLPD-NKs) are rare and heterogenuous. They are characterized by a persistent (> 6 months) increase in the peripheral blood NK-cell count without a clearly identified cause. It is difficult to distinguish between reactive and neoplastic conditions without highly specialized techniques. CLPD-NK is a proliferation of NK cells associated with a chronic clinical course and is considered a provisional entity.

Abstractor Notes

(This neoplasm is reportable for cases diagnosed 2010 and later.)

Many patients receive no treatment, some receive aspirin, others corticosteroids, or they may receive chemotherapy in low doses. Some patients have a splenectomy.

Definitive Diagnostic Methods

Bone marrow biopsy
Genetic testing
Peripheral blood smear

Genetics Data

STAT3 mutations
TR genes are clonally rearragned


CD2 positive
CD3 positive
CD4 positive and negative
CD8 positive and negative
CD16 overexpressed
CD57 positive or overexpressed
Granzyme B expression
Granzyme M expression
KIR positive
TCR-positive cytotoxic T cells (alpha beta and gamma delta)


Other therapy

Transformations to


Corresponding ICD-9 Codes

204.8 Other lymphoid leukemia

Corresponding ICD-10 Codes

C91.7 Other lymphoid leukemia

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

C91.Z Other lymphoid leukemia (effective October 01, 2015)

Progression and Transformation


Epidemiology and Mortality

Age: 45-75 years (rare before 25 years)
Incidence: 2-3% of all mature lymphocytic leukemias
Sex: no male or female predominance
Survival: indolent course over prolonged period, mortality associated with cytopenias (mostly neutropenia)


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 T- and NK-cell neoplasms
Pages: 348-352

International Classification of Diseases for Oncology, Third Edition, First Revision. Geneva: World Health Organization, 2013.
Section: ICD-O-3.1 (2011) Morphological Codes