Lamy and Loughram developed a flow diagram for evaluation of a patient with a proliferation of large granular lymphocytes (LGL) in the peripheral blood. This can help separate patients into different clinical groups which can aid clinical decision making. The authors are from H. Lee Moffitt Cancer Center in Tampa, Florida.


Patient presentation:

(1) clinical features (neutropenia with frequent infections; unexplained anemia; presence of rheumatoid arthritis; lymphadenopathy and/or hepatosplenomegaly)

(2) increased large granular lymphocytes in the peripheral blood (absolute count > 500 per µL). A person with <= 500 LGL per µL may also be included if the clinical syndrome is highly characteristic; however, there should be some present (I will use > 300 per µL in the implementation, but this is a guess).


Phenotypic studies on peripheral blood lymphocytes:

Type 1 (T cell): CD3 positive, CD57 positive, CD56 negative (rarely positive)

Type 2 (NK cell): CD3 negative, CD57 negative or weakly positive, CD56 positive


Workup Type 1: Perform rearrangement studies of the T-cell receptor (TCR) gene.

(1) If clonal: T-cell LGL leukemia

(2) If nonclonal: reactive T-cell LGL


Workup Type 2: Evaluate disease course.

(1) If aggressive: natural killer (NK) cell leukemia

(2) If not aggressive: reactive NK cell lymphocytosis (short term, weeks) or chronic NK cell lymphocytosis (long term, months or years).


To read more or access our algorithms and calculators, please log in or register.