Pathological Case of the Month FREE

Figure 1. Magnetic resonance imaging of the head shows a mass measuring 4.2 cm in diameter with cystic contents and small areas of nodular and rim enhancement. The mass causes marked compression of the cortical mantle throughout the inferior parietal and temporal regions.

Figure 2. Multiple mature germ cell elements are seen within the resected tumor. Mature cartilage can be seen adjacent to respiratory-type epithelium (periodic acid–Schiff, original magnification ×40).

Figure 3. Much of the tumor is composed of primitive neuroectodermal cells. Focally, medulloepitheliomalike differentiation is present, with the tumor cells forming primitive neural tubes (hematoxylin-eosin, original magnification ×40).

Congenital intracranial tumors are rare, accounting for 0.5% to 1.5% of all childhood brain tumors.¹ Data from the National Cancer Institute's Surveillance Epidemiology and End Results program suggest that the incidence of these tumors has increased during the past 20 years.²

The most common clinical presentation is macrocrania, hydrocephalus, and a bulging fontanel. Signs of increased intracranial pressure such as papilledema and nuchal rigidity are less frequent because of decompression through the cranial sutures. Other findings include paresis, cranial nerve deficits, convergence nystagmus (Parinaud syndrome), seizures, vomiting, and lethargy. A supratentorial location of the tumor is more common in infants than in older children. Differential diagnosis of supratentorial tumors includes astrocytoma, ependymoma, primitive neuroectodermal tumor, germ cell tumor, and choroid plexus papilloma. In a series studied at University of California–San Francisco, the most common brain tumor presenting or producing symptoms at birth was teratoma, occurring about 5 times more frequently than the second most common type, astrocytoma.³

In general, intracranial teratomas are extremely uncommon. Most are located in the pineal region, but about 20% are located in the suprasellar or infrasellar regions.⁴ Histologically they are classified as mature, immature, or teratoma with malignant components based on the amount of tissue differentiation. They contain structures derived from all 3 germ cell layers. Immature teratomas may also contain primitive neural tissue.⁵ They may produce plasma or cerebrospinal fluid markers such as α₁-fetoprotein and human chorionic gonadotropic hormone. Prenatal diagnosis has increased with the use of ultrasonography.⁶

Congenital intracranial teratomas have a poor prognosis. There are several cases reported in the literature of stillborn infants presenting with severe macrocephaly, history of polyhydramnios, and even skull rupture at delivery.^7- 9 Most of these infants die within the first few months of life and the longest survival reported has been 1.5 years.⁶

Treatment includes radical surgical resection of the tumor, followed by either radiotherapy and/or chemotherapy. The extent of surgical resection is an important prognostic factor.⁴ If the patient survives, radiotherapy is usually postponed until 24 to 36 months of age to avoid complications such as stunted growth, endocrine disturbances, and neuropsychologic problems.

Accepted for publication January 1, 1999.

Reprints: Eneida Rosario, MD, Department of Pediatrics, Rainbow Babies and Children's Hospital, 11100 Euclid Ave, Mailstop 6002, Cleveland, OH 44106.