In the interesting article on interphase argyrophilic nucleolar organiser regions (AgNORs) in transitional cell bladder tumours,¹ the authors conclude that the AgNOR score gives additional cell kinetic information, but that the clinical value of this technique is limited. Neither mean AgNOR count nor nucleoli numbers could distinguish between patients with superficial or invasive tumours because of considerable overlap. This was also the case when the AgNOR numbers of grade II and III tumours were compared.

Recently, we performed a study on the AgNOR pattern in urinary cytology, where the final diagnosis was done in each case by subsequent histological examination of bladder biopsies.² We found that AgNOR precipitations increased in parallel with the grade of malignancy, thus confirming the results of Korneyev et al.¹ There was also considerable overlap of the AgNOR counts between the …