Table 1. Definitive pathology findings from brain biopsy and associated interpretation of findings.

Marker	Results	Interpretation
CD 5	Negative	Decreased likelihood of T-cell lymphoma and chronic B-cell leukemia
CD 10	Negative	Decreased likelihood of acute leukemia and follicular lymphoma
CD 19	Positive	Highly suggestive of B-cell malignancy and available target for CAR-T and monoclonal antibody medications
CD 20	Positive	Suggests active B-cells; expressed in B-cell lymphomas
CD 23	Negative	Decreased likelihood B-cells involved in capturing IgE-antigen complexes
CD 38	Equivocal	Decreased likelihood that HIV seroconversion is occurring
CD 45	Positive	Increased likelihood of B-cell leukemia or lymphoma
FMC7	Positive	Strong likelihood of B-cell NHL or chronic lymphocytic leukemia [7]
Additional findings	Aberrant population (<1%) of lambda light chain restricted	Highly suggestive of malignant B-cell proliferation and movement away from normal kappa/lambda ratio of 1:1 to 1:2 [8]