Hospital General S. S. A. Acapulco, Guerrero, Mexico. Unidada Obstetrica Qururgica de Acapulco, Guerrero, Mexico. Instituto Mexicano de Diagnostico por Imagen, Mexico. Facultad de Medicina, Divison de Pos-Grado de la Universidad Autonoma de Guerrero, Mexico.

Case report

A 20-year-old G1P0 with unremarkable history, presented to our department at 32 week of pregnancy. An ultrasound investigation revealed a solid tumor with small hyperechoic and cystic areas, of a size 60 x 40 mm, protruding out of the oral cavity. The tumor was attached by a thin stalk to the tongue of the fetus. No other malformations were observed.

The tumor was increasing in size during pregnancy (at 34th week 70 x 45 mm, at 36th week 90 x 60 mm) and caused decreased swallowing of the fetus with consequent polyhydramnios and small size of stomach.

The findings were consistent with epignathus - congenital oropharyngeal teratoma.

The delivery was planned with cooperation of obstetricians and surgeons. The baby was delivered by the cesarean section with immediate ablation of the tumor using EXIT technique (EX utero Intrapartum Treatment - uterus was kept relaxed with the intact utero-placental blood flow and the foetus was supplied by oxygen via umbilical cord until the tumor was removed). The tumor was attached to the tongue of the baby by a thin stalk. The procedure was quickly done and the baby didn"t required intubation. Nowadays the baby is doing well.

Pathological examination of the tumor confirmed the diagnosis of oropharyngeal teratoma. Macroscopically we could see parts of the limbs, fingers, penis, and scrotum. The microscopic examination found areas of gastrointestinal tract, nervous, cartilage, and adipose tissues.

Images 1 and 2: 2D sonography at 32nd week. Images show irregular predominantly solid mass protruding out of fetal mouth.

Images 3 and 4: 2D sonography at 32nd week; Image 3 - gray scale image showing irregular solid mass with small cystic components protruding out of fetal mouth; and image 4 - color Doppler image showing vessels supplying the tumorous mass.

Images 5 and 6: 3D sonography at 32nd week; Images show tumorous mass protruding out of the fetal mouth.

Images 7 and 8: Perioperative images during the EXIT surgical resection of the epignathus protruding from the oral cavity attached to the tongue of the baby. The umbilical cord was left intact during the surgical procedure.

Images 9 and 10: Perioperative images during the EXIT surgical resection of the epignathus protruding from the oral cavity attached to the tongue of the baby. The umbilical cord was left intact during the surgical procedure.

Images 11 and 12: Final suture of the baby"s tongue after the EXIT surgical resection of the epignathus (image 13); and postnatal appearance of the baby after surgical resection of the epignathus (image 14).

Images 13 and 14: Pathological specimens showing the resected epignathus.

Definition

Epignathus is a rare teratoma arising from the oral cavity or pharynx. Most cases of epignathus arise from the sphenoid bone. Some arise from the hard and soft palate, the pharynx, the tongue and jaw. From their sites of origin, the tumors grow into the oral or nasal cavity or intracranially. The tumors, which are usually benign, consist of tissues derived from any of the three germinal layers; most of them contain adipose tissue, cartilage, bone, and nervous tissue. Epignathus can lead to death soon after birth due to severe airway obstruction. This emphasizes the need of thorough prenatal diagnosis and management of this condition.

In 1940 Ewing classified these nasopharyngeal tumors as:

1. Dermoids - consisting of epidermal and mesodermal germ layers, attached to soft / hard palate and / or pharynx near midline. Minimal or extensive intracranial extension may be present with skin cover.
2. Teratomas - consisting of all 3 germ cell layers with an indifferent degree of organization. It differs from type 1 by their greater structural complexities, earlier development and larger size.
3. Epignathus - consisting of teratomas with high degree of organizational and recognizable structures. Formed organs are present.

Jordan and Gauderer in 1988 [10], based on their personal experience and reviewing the literature, proposed a helpful classification of cervical teratomas and observed a 100% mortality rate in the non-operated patients. Our case was classified as group III according to Jordan and Gauderer.

Incidence

Congenital teratomas are rare tumors with an incidence of 2.5:10,000 live births. Those arising from oropharyngeal cavity comprise less than 2%. 60% occur in the nasopharynx, predominantly in girls.

Prenatal diagnosis

Ultrasound examination can demonstrate a solid tumor arising from the oral cavity; calcifications and cystic components may also be present. Polyhydramnios (due to pharyngeal compression) is usually present. A careful examination of the brain is important because the tumor may grow intracranially. The outlook depends on the size of the lesion and the involvement of vital structures. Lesions detected antenatally have been very large. Polyhydramnios has been associated with poor prognosis.

Maternal serum alpha-fetoprotein levels are always increased in this condition.

Differential diagnosis

Differential diagnosis includes neck teratomas, encephaloceles, and other tumors of the facial structures, congenital myoblastoma or epulis originating from the alveolar ridge.

Associated anomalies

Epignathus can be associated with other midline anomalies (Pierre Robin syndrome, meningoencephalocele, cleft lip, cleft palate etc.).

Prognosis

Epignathus can cause neonatal death due to airway obstruction and consequent asphyxia after birth. Surgical resection is generally needed. Its timing, management and results depend on the extent of the tumour. The vast majority of these tumors are benign lesions, but malignant variant can occur sporadically and some elements of these tumors may become malignant after incomplete removal. Because of asphyxia secondary to airway obstruction, the mortality rate is high in these patients during birth or shortly afterwards.

Management

When the prenatal ultrasonographic diagnosis of a giant mass protruding from the mouth of the fetus is done, genetic counseling and planned obstetric management with subsequent surgery in a specialized unit must be arranged. Post delivery the umbilical cord and fetoplacental circulation must be left intact to allow oxygenation of the fetus until a rapid examination and a tracheostomy is done, if it is necessary.

After airway is secured, the umbilical cord can be clamped and the baby can be transported to the neonatal intensive care unit and subsequent surgery can be done after baby"s stabilization. Before surgery, plain X-ray and computed tomography (CT) scan must be performed to rule out intracranial extension of the tumor or primary lesions of central nervous system. Radical disfiguring surgery is contraindicated in the neonate as it may result in impairment of speech and deglutition.

References