INTRACRANIAL TERATOMAS

• Contain all three germ cell layers.
• Usually benign, but grow rapidly, invade locally and do not metastasize.
• 2/3 supratentorially and thought to arise from the pineal gland.
• Usually diagnosed in the third trimester (earliest reported teratoma was at 22 weeks).

ULTRASOUND (1-5)

• Irregular.
• Solid echogenic mass with variable cystic components.

• Calcification (may be sonographically visualized).
• Distortion of the fetal brain; midline structures may not be identified.
• Majority are supratentorial.
  3 sites of predilection
• Within the third ventricle (having invaded from the pineal gland).
• Subfrontal.
• Subtemporal.
• Less frequently they may arise infratentorially.
• Can grow through the skull base into the neck, midbrain and orbits
• Increased BPD and hydrocephalus may occur, resulting in macrocrania with / without deformity of the calvarial shape.
• Polyhydramnios (>50%).
• Fetal hydrops and high output cardiac failure is rare (1).

Scan at 22 weeks of gestation.Solid subfrontal mass extending into temporal and parietal regions.Solid and predominatly cytic components.Mass effect and midline shift present. Dilated third ventricle

DIFFERENTIAL DIAGNOSIS

· TORCH infection.

· Ischemic brain necrosis.

· Other intracranial tumors (astrocytoma / neuroectodermal).

· Arachnoid cyst if the lesion is primarily cystic.

PROGNOSIS

• Very poor. Perinatal mortality is close to 100% (usually in the first few days of life).
• Prolonged survival is rare, but has been described.

REFERENCES

1. Scherer DM, Abramowicz JS Eggers PC et.al. Prenatal ultrasonic diagnosis of intracranial teratoma and massive craniomegaly with associated high-output cardiac failure. Am J Obstet Gynecol 1993;168:97-99.
2. Richard SR. Ultrasonic diagnosis of intracranial teratoma in utero: A case report and literature review. J Reprod Med 1987;32:73-75.
3. Ferreira O, Morvan J, Cleophax JP. Prenatal diagnosis of intracranial teratoma. A case report. J Gynecol Obstet Biol Reprod 1988;17:1075-1080.
4. Ferreira J, Eviatar L, Schneider S et.al. Prenatal diagnosis of intracranial teratoma: Prolonged survival after resection of a malignant teratoma diagnosed prenatally by ultrasound. A case report and literature review. Pediatr Neurosurg 1993;19:84-88.
5. Kuller JA, Laifer SA, Martin JG et.al. Unusual presentation of fetal teratoma. J Perinatol 1991;11:294-296.