Hello,
We do Anatomic Pathology service for a large children's hospital in Omaha.
Most of the cases we get for diagnosis of Hirschprung's are on paraffin
sections.  We do 8 serial sections with as many sections on a slide as we
can get.  
We have occasionaly done serials for ganglion cells on frozen sections.
Serial sections without wasting any tissue and beginning right "off the
top" are then important aspects of handling these cases.
Sometimes we get lucky and see ganglion cells on the first section.
unfortunately this is rare.
Jan Mahoney