Congenital cervical fibrosacroma with hydrops fetalis

Abstract

Congenital fibrosarcoma is a rare soft-tissue tumor of infancy. We report here a case of a congenital cervical fibrosarcoma associated with hydrops fetalis. A 24-year-old female who presented with preterm labor at 31 weeks of gestation was diagnosed by ultrasound scan to have a large neck tumor and hydrops fetalis. An ex utero intrapartum treatment (EXIT) procedure was performed at cesarean section to secure the fetal airway. The neonate died 2 h after delivery because of rapid clinical deterioration associated with hydrops fetalis and pulmonary hypoplasia. Postmortem examination revealed a diagnosis of cervical fibrosarcoma. Although the specific diagnosis of congenital fibrosarcoma may be difficult without histology, the prenatal diagnosis of a fetus with a large neck mass makes the prenatal counseling and the coordinated perinatal management of the airway with an EXIT procedure feasible. Congenital fibrosarcoma is a rare soft-tissue tumor of infancy occurring most commonly at the extremities and more frequently in male than female infants (1). With increasing use of routine antenatal sonography, a few cases of prenatally diagnosed congenital fibrosarcoma have been reported 2-6). We report the prenatal sonographic finding of a congenital fibrosarcoma of the neck associated with hydrops fetalis and pulmonary hypoplasia. Because of the size and position of the tumor, the baby was expected to have severe airway obstruction after birth, which could be difficult to manage. Our case illustrates the importance of prenatal diagnosis for an appropriate and coordinated perinatal management. A 24-year-old nulliparous female presented to her private obstetrician at 31 weeks of gestation because of preterm labor. She was immediately referred to our unit because of the sonographic diagnosis of polyhydramnios and a large fetal neck tumor. Upon admission, a repeated ultrasound scan confirmed a large right anterior neck mass measuring 10 × 6 × 5 cm with both cystic and solid components (1, 2). The tumor was avascular on Color Doppler ultrasound scan. The provisional diagnosis was cervical teratoma. The fetus also had features of hydrops, including cardiomegaly, bilateral pleural effusions (Fig. 2), ascites, and polyhydramnios, with the deepest pocket being 10 cm. The fetus was in a cephalic presentation, but the fetal neck was very laterally extended. The patient was in early preterm labor with regular uterine contractions and she was distressed by the abdominal distension. In view of the imminent need for delivery because of the distressing maternal symptoms and hydrops fetalis, tocolytics and antenatal corticosteroids were not given. Emergency cesarean section was performed because of the high risk of an obstructed labor. Longitudinal ultrasound scan of the fetus showing a large tumor mass (→) located at the fetal neck and massive pleural effusion. Transverse ultrasound scan of the fetus showing the cross-section of the tumor mass measuring 10 × 6 cm. Because of the position of the tumor, difficulty in securing a patent airway after birth was anticipated. Although the prognosis of this case was expected to be poor because of prematurity, the presence of the large neck tumor, and the development of hydrops fetalis, establishment of the airway was the only way to offer any chance to the neonate. Therefore, a multidisciplinary team was assembled to perform an ex utero intrapartum treatment (EXIT) procedure with the aim of securing the fetal airway at cesarean section while uteroplacental gas exchange was maintained. The team consisted of two obstetricians, one maternal anesthetist, two neonatologists, two pediatric otolaryngologists, one theatre-sister, two midwives, and one pediatric nurse. The mother was placed in a lithotomy position to allow optimal access to the fetal head for endotracheal intubation. She was given a general anesthesia. A lower segment transverse uterine incision was made, and the fetal head and shoulders were delivered and maintained in an occipito-posterior position. A 10 × 6-cm mass was noted at the right antero-lateral aspect of the neonates neck. The remainder of the fetus was not delivered while endotracheal intubation was attempted by the neonatologists and the otolaryngologists who stood by at the caudal end of the operating table. Endotracheal intubation by direct laryngoscopy was first attempted by an experienced neonatologist. Two attempts were made but were unsuccessful because of gross distortion of the larynx by the tumor. The pediatric otolaryngologists then used a rigid bronchoscope (size 2.5) to identify the laryngeal introitus. The bronchoscope was passed under direct vision through the glottis, but some difficulty was encountered in the subglottic region and gentle dilatation was performed. Subsequently, an endotracheal tube (size 2.5) with a stylet was successfully passed into the trachea. The correct position of the tube was confirmed by rigid bronchoscopy. This EXIT procedure took 12 min from the delivery of the fetal head. Delivery was then completed and the umbilical cord was clamped and cut. The umbilical cord arterial pH was 7.15, with a base excess of – 8.1 mmol/L. Routine closure of the uterus and abdomen was performed, and the anesthesia was reversed. Estimated blood loss was approximately 650 mL. A course of prophylactic antibiotics was given. The mother recovered well and was discharged on postoperative day 5. The neonate was resuscitated by the neonatalogists. In view of the bradycardia (heart rate 80 beats/minute), 1.6 mL of epinephrine at a concentration of 1 : 10 000 was given via the endotracheal tube and one dose of 30 µg atropine was given intramuscularly. External cardiac message was also started. Bilateral chest drain insertion and paracentesis were performed to relieve the pressure from pleural effusions and ascites. The Apgar score was one at 1, 5 and 10 min and 3 at 20 min. The heart rate was subsequently increased to 110 beats/minute. However, oxygen saturation remained at 30% even with the maximum settings of high-frequency mechanical ventilation, and the newborn died 2 h after birth. Hemoglobin at delivery was 9.8 g/dL. Post-mortem examination revealed congenital fibrosarcoma over the right antero-lateral neck extending to the anterior chest wall. The tumor was an infiltrative spindle cell lesion with areas of hemangiopericytic and fascicular pattern. There were small areas of necrosis and cystic changes in the center of the tumor. There was also severe bilateral pulmonary hypoplasia (left and right lungs weighed 9.9 g and 10.6 g, respectively). Congenital fibrosarcoma is a rare tumor. Approximately 150 cases have been reported in the English literature over the past 40 years (5). The tumor usually appears in the extremities, most commonly in their distal parts (7). Despite the potential for local recurrence, metastasis is rare and the prognosis is good after local excision (4). However, in our case, the uncommon location in the neck region led to a challenging perinatal management. To our knowledge, there are only five cases of prenatally diagnosed congenital fibrosarcoma reported in the medical literature, and in none of the reports has the correct diagnosis been made before histological examination 2-6). Our case is the second published case of congenital fibrosarcoma at the neck region. Other causes of a large fetal neck mass include cystic hygroma, lymphangioma, and teratoma. Cystic hygroma and lymphangioma are dilated lymphatic channels of various sizes. They have characteristic sonographic appearances of hypoechoic fluid-filled areas, which are different from our case (8). Teratoma is a neoplasm originating from pluripotent cells and is foreign to the anatomic site in which they arise. It is composed of tissues derived from any of the three primordial germ layers, with sonographic appearances of both cystic and solid components (9). The presence of both cystic and solid components in our case led us to establish the initial prenatal diagnosis of cervical teratoma. Out of the five published reports of prenatally diagnosed congenital fibrosarcoma, three revealed solid masses on an ultrasound scan (2, 5, 6), while the other two showed both solid and cystic components (3, 4). Therefore, fibrosarcoma should be one of the differential diagnoses for a solid fetal neck mass with or without cystic components. Hydrops fetalis is an uncommon association with neonatal tumors. So far, only one case of hydrops fetalis associated with fibrosarcoma has been reported (4): a male infant delivered at 32 weeks of gestation who presented with a huge thoracic fibrosarcoma and severe hydrops fetalis. The child could not be operated upon because of rapid clinical deterioration after delivery (4). Similar to our case, the neonate died soon after birth. The main cause of neonatal death in both cases was pulmonary hypoplasia, which was most likely secondary to the prolonged lung compression by bilateral pleural effusion. Therefore, the development of hydrops fetalis and pulmonary hypoplaisa is ominous and signifies a poor prognosis for fibrosarcoma. The pathogenesis of hydrops fetalis in fibrosarcoma is unknown. In the previously reported case the tumor was located at the mediastinum, and the authors proposed that it might be a result of high cardiac output failure or direct compression of major vessels by the tumor (4). In our case, the avascular nature of the tumor rendered high output cardiac failure unlikely. Severe hemorrhage into the tumor might lead to fetal hydrops. However, histological examination did not support a major degree of hemorrhage, and the mild degree of fetal anemia noted at birth (hemoglobin level of 9.8 g/dL) also could not account for the hydropic change. We postulated that direct compression of major vessels by the tumor might have played a major role. Although the diagnosis of fibrosarcoma was not made antenatally, the prenatal observation of a huge fetal neck mass allowed for the anticipation of postnatal airway obstruction. Experience from other large neck tumors suggests that they can be fatal if the airway is not secured at birth (10). Although a poor prognosis was expected in our case becaue of the presence of hydropic changes, the establishment of the airway after birth was the only way to offer any chance to the neonate, as hoped by the parents. As a result, the perinatal management at birth by an EXIT procedure was coordinated. The EXIT procedure provides time to secure an airway while uteroplacental gas exchange is preserved. It was originally described for the reversal of tracheal occlusion from in utero clipping in fetuses with diaphragmatic hernia (11). It has also been used to secure airways that are obstructed by fetal neck masses like cervical teratomas and lymphangiomas (12). The EXIT procedure enables the maintenance of uteroplacental blood flow and fetal gas exchange by only partially delivering the fetus. Normal cord blood gas values have been documented after up to 54 min on uteroplacental support (12). In this way, more time is available to perform the maneuvers that may be required to secure the airway. However, the EXIT procedure is not without risk to the mother. It has been shown that postpartum wound complications were more common in patients who underwent EXIT procedures compared with those who underwent elective cesarean section (15% vs. 2%, p < 0.05) (13). To our knowledge, this is the first report of a congenital fibrosarcoma that both occurs at neck region and is associated with hydrops fetalis and pulmonary hypoplasia. These two uncommon features of congenital fibrosarcoma have led to a great challenge in perinatal management. The benefits offered by an EXIT procedure in allowing more time for airway management at birth have to be balanced against maternal morbidity, particularly in cases with poor fetal prognosis, as signified by the development of hydrops fetalis. In this way, prenatal counseling and parental opinion are essential for an appropriate plan of management to be agreed upon. Although the precise diagnosis of a fibrosarcoma was difficult before the excision, the prenatal diagnosis of a large fetal neck tumor is important for prenatal counseling and a coordinated perinatal management.