Figure 4: X-ray of stillborn at autopsy. Numerous bones within epignathus are less mature than those of the infant itself.
Dissection of the tumor through its mid-hard palatine insertion revealed that the tumor extended through the nasal cavity into the cranium. The tumor was detected in both the temporal and posterior fossae on the right side. A large degree of ventricular enlargement was seen in the brain. Histologic sections revealed variable teratomatous tissue differentiation. These included primitive lung, skin, fibrovascular tissue, primitive intestinal structures, immature pancreas, immature neural tissue, cartilage and bone. The cytogenetics of the teratoma revealed a 46 XY normal male complement of chromosomes. The massive hepatomegaly and pericardial effusion were noticed.
Examination of the placenta revealed classical hydrops. The placenta weighed 500g and grossly showed flattening of the placental lobules.
Discussion
Synonyms
Synonyms include oral teratoma, nasopharyngeal teratoma, extra- gonadal teratoma, facial teratoma.
Definition
A teratoma which arises from the oral cavity and/or pharynx.
Incidence
Teratomas, being the most common neoplasms in the newborn, occur at a rate of one in 35,000 live births. About 2% of all pediatric teratomas occur in the nasopharyngeal area.
Etiology
The midline location of most congenital teratomas has served to support the hypothesis that primordial germ cells migrate along the dorsal midline from the hindgut-yolk sac region into the embryonic genital ridge. Some cells continue their cephalad migration to eventually settle in the mediastinum, neck, nasopharynx, and brain (pineal and hypothalamic regions).
Pathology
Most teratomas have at least one tissue type from each of the three embryonic layers. Regardless of the primary site, teratomas have several pathologic features in common. The cystic or multicystic components are usually accompanied by solid areas that often have a brain-like tissue quality. Hemorrhage is inconspicuous, with the exception of those tumors subjected to trauma during delivery. Tumor-related necrosis is usually minimal because these neoplasms are rarely malignant.
Associated anomalies
Associated anomalies are seen in approximately 6% of these cases2 and include facial clefts, bronchial cysts, hypertelorism, and congenital heart defects.
Diagnosis
The prenatal diagnosis of epignathus is based on the sonographic visualization of a complex mass emanating from the fetal mouth and/or nose. The solid areas are composed of tissues of different density; they may also include calcific areas of tooth and bone. Hyperextension of the head has been reported in fetuses with epignathus. The ultrasound diagnosis is based on the detection of the mass arising from the fetal face. Polyhydramnios is usually present secondary to the obstruction of fetal mouth and inability to swallow. Our particular interest in this case is the development of fetal heart failure, as evidenced by hepato- and placentomegaly as well as fetal echocardiographic changes. Fetal heart failure and mechanical occlusion of the fetal mouth by the tumor are probable contributors to the development of polyhydramnios in this case. The mechanism of fetal heart failure in cases of epignathus is probably similar to the one in fetal sacrococcygeal teratomas: high output cardiac failure.
Prognosis
Nasopharyngeal teratomas are often associated with polyhydramnios, nonimmune fetal hydrops, and exophathalmos. Although the majority of these tumors are benign in nature, fetal and neonatal death is very common due to the local mass effect, which produces life-threatening dysfunction (basocranial teratomas) or cessation of function (respiratory compromise from a nasopharyngeal or cervicothyroidal lesions). Most cases reported in the literature revealed dismal outcome4-6.
Differential diagnosis
Epignathus should be differentiated from cystic hygromas, which are often located in the neck area. Both lesions can be associated with nonimmune hydrops fetalis. Cystic hygromas are located outside fetal cranial and facial structures, predominantly in the lateral and posterior neck regions.
Recurrence
No cases of epignathus occurring in subsequent pregnancies were described in the literature. Nasopharyngeal tumors are rare and comprise only two percent of all neonatal teratomas.
Management
In those cases where the lesions were diagnosed early in the course of pregnancy, parents should be informed of the guarded prognoses and offered an option to terminate the pregnancy.
If the fetus is viable at the time of diagnosis, most authorities advise a cesarean section as a route of delivery. A pediatric surgeon and an experienced neonatologist should be present at the time of delivery to provide immediate resuscitation, endotracheal intubation and even a tracheotomy if an airway cannot be secured.
Conclusion
In conclusion, both distorted intracranial anatomy and heart failure may further complicate prognosis and outcome in fetuses with epignathus and should be included as potential complications during patient counseling.
References
1. Barson AJ.Ā Congenital neoplasia: The society experience. Arch Dis Child 53:436, 1978.
2. Gilman PA: Epidemiology of human teratomas. In Damjanov I, Knowles BB, Solter D (Eds): The Human Teratomas. Experimental and Clinical Biology. Clifton, New Jersey, Humana Press, 94, 1983.
3. Stocker JT, Dehner LP (Eds). Pediatric Pathology. 328-33, JB Lippincott Co, Philadelphia, 1992.
4. Chervenak FA, Tortora M, Moya F, et al: Antenatal sonographic diagnosis of epignathus. J Ultrasound Med 3:235-7, 1984.
5. Kaplan C, Perlmutter S, Molinoff S. Epignathus with placental hydrops. Arch Pathol Lab Med 104:374-5, 1980.
6. Romero R, Pilu G, Jeanty P, et al: Prenatal Diagnosis of Congenital Anomalies. Appleton & Lange, Norwalk, 106-8, 1986.
7. Chervenak FA, Isaacson G, Lorber J. Anomalies of the fetal head, neck, and spine. Ultrasound Diagnosis and Management. WB Saunders Co, Harcourt Brace Jovanovich, Inc., Philadelphia, 39-51, 1988.
8. Nogales FA, Gasca L, Llamas R, et al: Epignathus: clinical, radiological, and pathological considerations. Int J Gynecol Obstet 15:41-3, 1977.
9. Kang KW, Hissong SL, Langer A: Prenatal ultrasonic diagnosis of epignathus. JCU 6:330-1, 1978.