Lymphocytosis is defined by an excess of lymphocytes in the blood. In staging of Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL), lymphocytosis is defined as an absolute lymphocyte count (ALC) greater than 5,000 cells/µL.

Lymphocytosis is a prognostic factor required for staging of Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia (CLL/SLL) in AJCC 8th edition, Chapter 79 Hodgkin and Non-Hodgkin Lymphomas. It is a new data item for cases diagnosed 1/1/2018+.

0	Lymphocytosis not present Absolute lymphocyte count = 5,000 cells/ µL
1	Lymphocytosis present Absolute lymphocyte count > 5,000 cells/µL
6	Lab value unknown, physician states lymphocytosis is present
7	Test ordered, results not in chart
9	Not documented in medical record Lymphocytosis not assessed or unknown if assessed

Each Site-Specific Data Item (SSDI) applies only to selected primary sites, histologies, and years of diagnosis. Depending on applicability and standard-setter requirements, SSDIs may be left blank.