Influence of intratumour heterogeneity in the interpretation of marker results in phaeochromocytomas
Krijger et al.1 try to predict the clinical behaviour of a phaeochromocytomas (PCCs) on the basis of the immunoreactivity of three markers (p53, bcl-2, and c-erbB-2). They conclude that the co-expression of p53 and bcl-2 proteins may assist that prediction. Our own preliminary results2,3 mainly agree with theirs and point towards two interrelated biological issues: firstly, the clonal evolution of neo- plasms and intratumour heterogeneity of markers; and secondly, the importance of apoptosis in tumour initiation and progression.
Krijger et al. clearly indicate the importance of p53 and bcl-2 in the pathogenesis of a subgroup of PCCs. However, the variability of marker expression and the potential relationship with kinetic features are also helpful in understanding the pathogenesis of PCC.
