Gating strategies used to interrogate the neoplastic and non-neoplastic cell populations.

<p>Following exclusion of dead cells and debris, two different gating strategies were employed to evaluate the cells isolated from lymph node aspirates. For the purposes of generating an immunophenotyping profile, an upper 30% gate was applied to identify the population of largest events, enriched in neoplastic cells. The immunophenotype was then determined using a 60% expression threshold within this population. For the purposes of evaluating frequencies of T cells within fine needle aspirates of B cell lymphoma (BCL), reactive hyperplasia (RH) and mast cell tumour (MCT) cases, an ‘All’ gate was applied and then the populations subsequently delineated by means of CD5 expression. Non-neoplastic cells were identified as CD5⁺ and neoplastic populations CD5⁻ in the context of BCL; TCL cases were excluded from such comparisons on account of their CD5 expression by both neoplastic and non-neoplastic cells.