A sonographic test (Ultrasound) revealed an almost solid Polypoid mass about 10X12 in size growing at the front of the babies neck, which appeared to be protruding from the babies mouth. Due to it's appearance, a teratoma was considered, but everything else about the baby (her skull and spinal column) seemed normal, so they left it alone.
At week 33, the mother was experiencing accelerating hydramnios (excess amniotic fluid) and uterine contractions, the doctors decided to perform a caesarian section and the little baby girl was born. The baby had difficulty breathing, had a low heart rate (<90) and passed away 15 minutes later with a large tumor protruding from her mouth.
Under a microscope the tumor revealed a variety of tissues, including neural tissue, cartilage, bone, sebaceous glands and respiratory epithelium, typical teratoma (substances in a tumor which are not normally present at the site), the site being the gonads, the reproductive organs like the testes or ovary. There was a presence of partially formed organs.
Because the tumor showed a certain degree of organization, it was considered a parasitic fetus.
Congenital teratomas have an occurrence of 1 in 4000 live births and only 117 cases have been reported since the first reported case in 1918.