Thrombocytopenia is defined by a deficiency of platelets in the blood. In staging of Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL), thrombocytopenia is defined as Platelets (Plt) less than 100,000/μL.

Thrombocytopenia is a prognostic factor required for staging of Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (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	Thrombocytopenia not present Platelets (Plt) = 100,000/µL
1	Thrombocytopenia present Platelets (Plt) < 100,000/µL
6	Lab value unknown, physician states thrombocytopenia is present
7	Test ordered, results not in chart
9	Not documented in medical record Thrombocytopenia 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.