LAUSR

T‐cell clonality testing by T‐cell receptor (TCR) gene rearrangement is key to the diagnosis of T‐cell lymphoproliferative disorders such as T‐cell large granular lymphocytic (T‐LGL) leukemia. Benign clonal T‐cell expansions, however, are commonly found in patients without identifiable disease, a condition referred to as T‐cell clones of uncertain significance (T‐CUS). In practice, T‐cell clonality testing is performed for a range of reasons and results are often challenging to interpret given the overlap between benign and malignant clonal T‐cell proliferations and uncertainties in the management of T‐CUS.