“…Furthermore, somatic hypermutations of the IgH gene, acquired while traversing the germinal centre, may cause false negative results on IgH PCR 6. This was demonstrated by Kang et al , who showed that compared to the 100% concordance noted between morphology and PCR based clonality in small lymphocytic lymphoma, follicular lymphoma showed a concordance of only 66%, whereas diffuse large B-cell lymphoma (DLBCL) showed an even lower concordance of 57% 7. Recently however, newer methods based on the standardised BIOMED-2 protocol have used multiplex assays employing several upstream primers that have increased the sensitivity of IgH PCR 8.…”