# Antenatal Sonographic Diagnosis of Pharyngeal

Authors: M. Varras; Ch. Akrivis; Ch. Plis; G. Tsoukalos
Journal: Obstetrics and Gynecology International
 (2009)

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## Abstract

Background. Teratomas are the most common tumors. They are usually localized in the sacrococcygeal area, while the pharyngeal localization is very rare. The number of cases of stomatopharyngeal teratomas detected prenatally via sonography is very small. Case Report. We present the case of a 24-year-old primipara at 18 weeks' gestation, that at the routine ultrasound scan, the fetus was found with an echogenic mass, filling the stomatopharyngeal cavity and protruding from the mouth. Other abnormalities were not found. Termination of pregnancy was achieved using misoprostol. A female stillborn fetus with a weight of 250 g and length of 25.5 cm was delivered. The postmortem and pathologic examination confirmed the diagnosis. Conclusion. Pharyngeal teratomas can be diagnosed with the use of ultrasounds in utero facilitating parents' counseling in early time.


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## Body

## 1. Introduction

Teratomas are tumors  developed
from totipotent  stem cells and contain tissues of ectodermal, endodermal, and
mesodermal origin [1]. A fetal teratoma originating from the base of the skull
is called pharyngeal teratoma or epignathus [2, 3]. It is a rare, congenital
teratoma that is attached to an intraoral surface, most often palatal or
pharyngeal and is not normally associated with other anomalies
[3–6]. It
usually carries a poor prognosis [7]. Complications include polyhydramnios,
preeclampsia, preterm delivery, and respiratory compromise after birth due to
upper airway obstruction by the mass [5, 7]. We report a case of pharyngeal
teratoma with ultrasonographic and postmortem descriptions and review
literature.


## 2. Case Report

A healthy 24-year-old
primigravida was presented to the Department of Obstetrics and Gynaecology,
Tzaneio General State Hospital, Piraeus, Greece, for the first visit of her
pregnancy. The combined nuchal translucency and biochemical markers screening
test for aneuploidies between the 11 and13+6 weeks of pregnancy or the
ultrasound fetal measurement and quadrant blood test (AFP, free beta-hCG, free
oestriol, and indibin A) during the second trimester of pregnancy were not
performed. She was healthy, used no medication, had not been exposed to known
radiation and there were no malformed neonates within her family. Sonographic
examination revealed a single live fetus, 17+5 weeks of gestation with
biparietal diameter of 44 mm, head circumference of 155 mm, femur length of 26 mm, and abdominal circumference of 144.5 mm. There was a complex mass filling
the oropharynx and emerging from the fetal mouth
(Figures 1 and 2). The placenta
was located on the uterine fundus. The amount of amniotic fluid was increased,
but the rest of the examination was normal. The differential diagnosis included
hemangioma, teratoma, or a tumor of neural origin. After appropriate counseling
concerning the poor prognosis, the parents decided to terminate the pregnancy
at the 18 weeks’ gestation. Labor was induced with vaginal misoprostol and a
250 g stillborn female neonate was delivered with a tumor protruding through the
open oral cavity
(Figures 3 and 4).Figure 1
Longitudinal sonogram of the
fetal head at 18 weeks’ gestation shows a complex mass (arrow) filling the
oropharynx and spilling out the fetal mouth.The 3D ultrasound
scan shows the relationship of the mass with the mouth and the face.
(a)(b)(c)(d)Figure 3
Photograph of the stillborn infant shows the tumor
protruding through the open oral cavity.Figure 4
Photograph of the stillborn infant shows the tumor
protruding through the open oral cavity.The autopsy  revealed an
exophytic palatine mass that measured 6 × 4 × 2 cm and was attached to the
oropharynx and nasopharynx. Histological analysis confirmed the diagnosis of
pharyngeal teratoma. There were no additional malformations or fetal
chromosomal aberrations. Also, parental chromosomes were normal. The parents
were reassured that this  was a sporadic occurrence and that recurrence risk was
extremely low.


## 3. Discussion

Teratomas are the most common
congenital neoplasms, which account for 25–35% of all neonatal tumors and
present with an incidence of 1 in 20 000 to 1 in 40 000 live births [2, 8, 9].
However, teratomas involving the pharynx and the base of the skull present with
a frequency of less than 1% of all congenital teratomas [3]. Teratomas usually
occur more frequently in females than in males with a ratio of 3:1 [2]. They
generally contain derivatives of two or three germ cell layers and may be
classified as mature, immature or malignant based on their histopathologic
appearance and behavior [9]. Brain tissue is the most frequent component, but
cartilage, bronchial epithelium, and ependymalined cysts are common  [9].
Teratomas involving the pharynx and the base of the skull arise from cells of
the oral membrane, around the pouch of Rathke, and are in the vast majority
benign [9, 10]. There is no evidence to suggest environmental risk factors in
the pathogenesis of pharyngeal teratoma [2]. Furthermore, there are no
karyotype abnormalities involved and these lesions are not thought to be
inherited in a Mendelian or polygenic fashion [2, 7, 11].The clinical presentation of
congenital pharyngeal teratoma varies. Maternal serumα-fetoprotein assays are
usually used to screen for neural tube defects and autosomal trisomies.
However, elevated levels of maternal serum α-fetoprotein have also been
reported in pregnancies with fetal defects such as tracheoesophageal fistula,
esophageal obstruction, sacrococcygeal teratoma, and anorectal atresia. The
physiological mechanism of maternal serum α-fetoprotein elevation in
teratomas is probably the loss of fetal serum into the amniotic cavity  combined
with esophageal and tracheal obstruction by the mass [9]. The high levels of
maternal serum α-fetoprotein
can lead to a sonographic investigation and the diagnosis of the tumor [2]. It
may also be detected on routine sonographic examination, as in our case.
Teratomas generally appear as both solid and cystic on sonograms [2]. The solid
component is often nonhomogenous, composed of tissues of different density
such as cartilage and liver and may contain calcifications that may be tooth or
bone. The cystic spaces are irregular and are formed by cavities lined with
neural, respiratory, gastrointestinal or squamous epithelium [2]. These tumors
frequently cause increase of the amniotic fluid as in our case, due to
inability of the fetus to swallow the amniotic fluid. Also, these tumors
frequently cause palatal clefting [10]. In our case cleft was not detected in
the palate and this was also confirmed by the postmortem examination. In
addition, in the present case, 3D ultrasound scan was helpful in assessing the
external fetal anatomy and had provided images that were understandable by
parents thus facilitating counseling (Figure 2).The prognosis of pharyngeal
teratoma is poor [2, 11]. It depends mainly on the size of the lesion and the
involvement of vital structures [2]. In two reviews comprising 33 neonates with
epignathus, 12 expired in utero or immediately after birth [12, 13].
Most deaths were attributed to airway obstruction. Also, difficulty in feeding
is a common symptom for neonate with pharyngeal teratomas.


## 4. Conclusions

Pharyngeal teratomas can be
suspected with the use of ultrasounds in utero facilitating parents’
counseling in early time. However, the final diagnosis of pharyngeal teratomas
is ultimately a pathological diagnosis. If the parents decide to continue the
pregnancy, consideration should be given utilizing the exit procedure for air
management at delivery. Finally, it is important to reassure parents that they
are not at increased risk of bearing another child with these lesions.



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*Source: 180643-2009-04-02.xml*