Mature teratoma associated with an interparietal encephalocele. Case report.

Teratomas and encephaloceles are both uncommon congenital malformations that originate near the midline in the head and neck. An encephalocele is an extracranial extension of intracranial structures through a defect in the skull, whereas a teratoma consists of tissue from all three embryonic germ layers and is a true congenital tumor. In the present study the authors describe the first reported case of a mature teratoma associated with an interparietal encephalocele presenting as a large midline subcutaneous mass in a newborn child. The appearance of these two pathological entities together suggests a common origin. The embryological significance of this finding is discussed, and the pertinent literature is reviewed.