Vestibular schwannoma in pregnancy
Vestibular schwannoma in pregnancy poses a management dilemma. It is rare but when vestibular schwannomas occur in pregnancy they tend to be larger and grow faster than in men and non-pregnant woman. Long before MRI was available to evaluate these uncommon tumours, Harvey Cushing, famous neurosurgeon, already in 1917 described that vestibular schwannomas grow faster in pregnant woman.
The observation that vestibular schwannomas occur more commonly in female patients compared to male patients led to the question whether estrogen and estrogen receptors may not be responsible for the rapid growth in pregnancy. Vestibular schwannomas may grow faster due to either direct tumour stimulation by perhaps estrogen or due to increase vascularity or blood supply that usually occurs in pregnancy.
It is not clear in the literature to what extent estrogen stimulate growth in vestibular schwannomas. The fact that the estrogen receptors may be absent in some tumours may be due to the fact that we do not look well enough or that our tests to detect them are not sensitive enough. Even progesterone, the other hormone that increases in pregnancy has been investigated, with the same equivocal results. Needless to say is that there is not a lot of information published in the literature on the whole issue in any case.
A large rapid growing vestibular schwannoma in pregnancy is not fun. Magnetic resonance imaging (MRI) of a suspected tumour is fortunately considered safe during pregnancy. The management however, poses a risk to the mother and baby, more so perhaps to the baby in the first trimester and more so perhaps to the mother in the third trimester. The safest if surgery is to be performed is probably the second trimester. Any informed decision however should involve careful consultation and discussion between the mother, obstetrician, neurotologist, neurosurgeon and other involved parties.