Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone.
Nasal NK-cell lymphomas lacked clonal rearrangement of both T-cell receptor (TCR) gamma and immunogloulin heavy chain (IgH) genes and were either CD3(Leu4)-CD56+ (8 cases) or CD3(Leu4)+CD56+ (2 cases), whereas nasal T-cell lymphomas had rearranged TCRgamma and germ-line IgH genes and were either CD3(Leu4)+CD56+ (2 cases) or CD3(Leu4)+CD56- (1 case).
TCR-beta, TCR-gamma and immunoglobulin heavy chain (IGH) genes were analysed using PCR in 55 cases of T cell lymphoma (28 frozen tissue and 27 paraffin wax embedded samples), diagnosed using morphological and immunohistochemical criteria.