Fetus in fetu: a medical curiosity—considerations based upon an intracranially located case
A male newborn (a son of a 19-year old primiparous healthy mother—delivery was by cesarean section in the 33rd week of gestation, family history of multiple births was not remarkable) was admitted to the Intensive Care Department of the University Children’s Hospital in Kraków in the first day of life due to a large intracranial tumor. The tumor was diagnosed in the 31st week of gestation during routine ultrasound examination and confirmed by MRI (Fig. ). The pregnancy was terminated in the 33rd week of gestation with prior induction of lung maturation by dexamethasone administered to mother.\nThe newborn was presented in a grave state with symptoms of respiratory failure. A large partially intracranial tumor with a diameter of 9 cm was found. The tumor distorted child’s head and was covered by grayish blue skin. The eyeball was dislocated with exophthalmos.\nLow levels of serum proteins, hypoglycemia, dyselectrolytemia, and metabolic acidosis were found in laboratory tests. The level of AFP was 183,173.6 ng/ml. There was no cardiac defect or other abnormalities in the abdomen. CT confirmed that the tumor is expanding within the structures of the craniofacial region of his head (Fig. ).\nIt has been decided to remove the tumor surgically immediately, to give the child the chance of survival (Fig. ). However, just at the moment of introduction to anesthesia, the child abruptly deteriorated and the operation has not been started. Eventually, the child died the next day.\nThe general autopsy showed that the male newborn has a weight of 3,100 g, with features of fetal respiratory distress syndrome (Fig. ). Apart from the head which measures 44 cm in diameter, no other abnormalities in the child’s body were found.\nThe large tumor of 9 cm in diameter occupied the right anterior, medial, and pterygopalatinal cranial fossae, partially displacing the child’s brain to the left. The tumor was entirely encapsulated and connected to the rest of the body by a distinct vascular stalk (Fig. ). It caused a significant destruction and an enormous defect of the cranial vault measuring 8 × 7.5 cm and 5.5 cm deep.\nAfter the incision of the capsule, four relatively well-developed limbs (with fingers) appeared, protruding from the rest of the rather featureless tumor mass (Fig. ). Microscopically, apart from the relatively well-formed musculoskeletal structures of limbs (Fig. ) that were covered with skin (Fig. ), there were haphazardly distributed different tissues or fragments of organs like intestine (Fig. ), glands, muscles, and fat tissue. However, different neuroectodermal derivatives, like structures resembling primitive neural tubes, ganglions, neuroglial, and ependymal structures, were dominant (Fig. ).\nThere was no complete genetic profile obtained from histological materials, just individual genetic features in some STR structures. Examination of amelogenin gene in three specimens revealed chromosome X and Y characteristic for male sex.