ABSTRACT
Fifty percent of childhood cancer occurs under the age of five
years1 and clear evidence of inheritability exists in many
childhood tumors. Although benign tumors and masses are
not uncommon, malignant tumors are rare during the
perinatal period.2 Their behavior is variable and certain
apparently benign neonatal masses (e.g. teratomas) may
undergo malignant change if untreated. On the other hand,
others (e.g. neuroblastoma) may behave relatively benignly
and even mature in the neonatal period. Many of these tumors
respond to therapy and have a good prognosis, but the
mortality rate is estimated to be 6.26 per million live births.3,4
The hypothesis that tumors (and even adult cancer) may be
linked to or even initiated during fetal development57 is
supported by an ever-increasing number of animal experi-
mental studies. This makes the study of neonatal tumors
particularly interesting as a possible explanation of their early
(as opposed to later) appearance may lie in the developmental
processes still active in the host. Possible reasons for this are
based on the hypothesis that either genetic or environmental
(e.g. nutrition and exposures to environmental toxins) factors
(or both) may act as oncogenic promotors during gestation.8
