Central review of bone marrow trephine biopsies obtained between Janua
ry 1990 and July 1996 from 282 children with neuroblastoma showed that
18% of cores from older children and an unacceptably high 36% from in
fants were inadequate (p = 0.0002). Centres should choose their operat
ors for this invasive investigation of infants with more care in order
to reduce the failure rate.