Congenital teratomas are relatively rare tumors of childhood, accounting for a reported 3% of all childhood malignancies.3 Although they are observed in various midline and extra-axial anatomical locations at birth, they display a particular tendency to occur in the sacrococcygeal and presacral regions.3, 8 Tumors at these sites have a reported incidence of between 1: 20,000 to 1: 40,000 births, comprising 40 to 70% of all reported teratomas in most series.8, 14 A strong female predominance is also commonly reported.8, 14

By comparison, oropharyngeal teratomas are exceedingly rare, accounting for only 2% of all teratomas.8, 21 These tumors are often diagnosed prenatally; ultrasound examination usually confirms the diagnosis following the observation of maternal polyhydramnios. Oropharyngeal tumors generally present as large masses protruding from the mouth.8, 14 Their intrauterine growth may contribute to varying degrees of craniofacial malformations.8, 14 Despite a usual benign histopathology, oropharyngeal tumors are potentially lethal due to airway obstruction and respiratory compromise. Principles of management in these cases include immediate postpartum establishment of a secure airway, via tracheostomy if necessary, and complete surgical resection of the mass.

Even more uncommon than teratomas confined strictly to the oropharynx are teratomas with both oropharyngeal and intracranial components. A thorough review of the medical literature yields descriptions of only 30 such cases over the past 150 years. (Table 1) One-half of these patients were either stillborn or died shortly after birth from their disease. Of the remaining, a majority suffered significant morbidity or remained with residual disease following surgical management.

We present the unique case of an oropharyngeal teratoma with intracranial extension. The tumor, diagnosed at birth, was centered about the left maxillary sinus and extended into the left nasopharynx, oropharynx, infratemporal fossa, orbit, and left middle cranial fossa. The craniofacial component of the tumor was resected in the neonatal period via transfacial and transoral approaches. Removal of the intracranial lesion was deferred until nearly a decade later and was performed via a lateral approach to the skull base and infratemporal fossa. Currently, the patient is disease free and demonstrates no neurological, functional, or cosmetic deficits. We believe this is the first reported case of an oropharyngeal teratoma with intracranial extension in which complete staged surgical resection was performed without any complications and with such prolonged survival.

Case Report

This male patient was born in a community hospital at full term via a normal spontaneous vaginal delivery to a G3P2 27-year-old white female. The pregnancy and delivery were uncomplicated. There was no history of polyhydramnios during gestation, nor any indication of masses on routine ultrasound examination. Apgar scores were 6 at 1 minute and 8 at 5 minutes. The patient's birthweight was 3970 g.

The patient was orally intubated immediately postpartum due to respiratory compromise, but was able to be extubated one hour later following stabilization of his respiratory function. He was transferred to a tertiary care referral center for further evaluation of an observed facial asymmetry and suspected left facial mass. CT scan of the head and facial bones obtained at that institution indicated the presence of a soft tissue mass in the face. The tumor was centered within the left maxillary sinus and extended to the inferior floor of the orbit, the infratemporal fossa, the middle cranial fossa, and the right and left ethmoid air cells. On the fifth day of life, the patient underwent surgical resection of the tumor via a bucco-gingival incision. Cystic and solid components of the tumor were identified as it was removed from the midface, inferior orbit, and infratemporal fossa. While the bone of the orbital floor was found to be completely eroded, the periosteum containing the orbital contents remained intact. The optic and infraorbital nerves were not involved by tumor. The intracranial component of the tumor was not resected. The patient tolerated the procedure well and was extubated within 48 hours of surgery. However, persistent respiratory distress required reintubation and mechanical ventilation, prompting additional radiological evaluation.

MRI of the skull base identified an ovoid mass in the nasopharynx causing severe narrowing of the airway. Subsequent endoscopic examination of the nasal passages confirmed the presence of bilateral choanal obstruction by a soft tissue mass covered with a mucosal surface. At one month of age the patient returned to the operating room to undergo a transoral, transpalatal resection of the tumor. The lesion was based along the nasal surface of the soft palate at the lateral wall of the nasopharynx. It was removed in its entirety and the soft palate defect was repaired. The patient was successfully extubated following this procedure and was discharged home without any further complication.

Pathological analysis of the original facial specimen revealed cystic areas lined by epidermis and melanin-containing epithelium. Also noted were mature hair follicles, sebaceous glands, bone, and nervous tissue. All these findings were consistent with a diagnosis of mature teratoma.

The oropharyngeal specimen also contained mature structures from all three germ layers, including peripheral nervous tissue, fat, smooth muscle, and cysts lined with squamous and ciliated columnar epithelium. Also noted were focal areas of immature neural tissue. A diagnosis of mature teratoma with focal immature neuroglial elements was made. Neither of these specimens contained any evidence of malignant tissue.

The residual intracranial portion of the tumor was monitored throughout the patient's infancy and childhood with periodic physical and radiological examinations. Asymptomatic tumor extension into the infratemporal fossa was noted during this period and also observed. During the ensuing eight years normal developmental, speech, and growth milestones were met. There were no complaints of neurological deficiency or craniofacial abnormality. At the age of 8, however, the patient presented to a regional children's hospital complaining of severe left retroorbital headache and left ocular pain. MRI examination of the skull base revealed enhancement of the cystic components of the previously stable intracranial and infratemporal fossa masses. The infection responded to antibiotic therapy and the patient presented to our service following that hospitalization seeking definitive treatment.

The patient was electively admitted to our institution at 9 years of age for surgical removal of intracranial teratoma. A frontopterional craniotomy was performed to gain access to the floor of the middle fossa, which was resected from its lateral extent to the clivus. A grossly cystic tumor was exposed near the midline. A smooth epithelial surface lined a cavity filled with thick, turbid fluid. The cyst was evacuated and all intracranial and extracranial extensions of its wall were defined and resected. Surgical margins were first confirmed grossly via endoscopic examination of the tumor cavity, and then by frozen section analysis of samples taken from the periphery of the surgical field, all of which were determined to represent areas of scar tissue. Following completion of the tumor resection, the skull base was reconstructed using a flap of temporalis muscle and a fat graft harvested from the abdomen.

Pathology of the lesion was consistent with a mature teratoma. The epithelial lining contained flattened and columnar cells aggregated in clusters. The specimen also contained foci of mature bone, peripheral nerve, and central nervous tissue.

The patient tolerated the procedure well and had an uneventful recovery from surgery. He was discharged home one week after the operation with no neurological deficits or esthetic asymmetries and continues to do well. A recent MRI of the head and skull base at 1-year follow-up shows no evidence of intracranial or extracranial disease.

Discussion

Teratomas are congenital tumors that are composed of tissues derived from all three embryonic germ cell layers. They are thought by some authors to represent failed attempts at twinning. Others classify teratomas as true neoplastic growths arising from primitive germ cells that have escaped normal developmental regulation.8 Willis 26 defines teratomas as true neoplasms comprised of tissues of multiple embryological origins that are all foreign to the site in which they arise. Discrepancies in the nomenclature used to describe these tumors do exist in the medical literature. However, four basic histological classifications are generally recognized.5, 16 Dermoids are comprised only of epidermal and mesodermal elements. Teratoids are poorly differentiated tumors containing ectodermal, mesodermal, and endodermal tissues that are only loosely organized. True teratomas are also tumors containing tissues from all three cell layers. However, in contrast to teratoids, these exhibit greater histological organization and cellular maturity. Epignathi are tumors that consist of fully developed organs and appendages. Some authors continue to use this term to describe any tumor originating from the palate or oral cavity, regardless of cellular composition. Although the vast majority of teratomas are histologically benign, reports of malignant teratoma do exist. In addition, immature cellular components are associated with a greater likelihood of malignant degeneration.

Oropharyngeal teratomas are generally diagnosed in utero, either during routine prenatal ultrasound examination or during diagnostic workup for maternal polyhydramnios. Obstructive lesions that prevent fetal swallowing of amniotic fluid may contribute to the development of polyhydramnios during pregnancy. Masses with both cystic and solid components are highly suggestive of teratoma. The presence of calcifications on plain films of the head is also supportive of this diagnosis. Magnetic resonance imaging is useful in defining the anatomical relationships of these tumors and identifying associated central nervous system defects. Differential diagnosis of oropharyngeal teratomas includes ectopic brain tissue, frontonasal meningoencephalocele, craniopharyngioma, glioma, angiofibroma, rhabdomyoma, rhabdomyosarcoma, and lymphoma.

The basic principles for management of oropharyngeal teratomas are to guarantee a secure airway and to completely resect the tumor. Some authors call for the presence of a surgeon in the delivery room in cases where the diagnosis is made antenatally. Distortion of the intraoral anatomy may make oral intubation difficult in the event of respiratory failure, necessitating emergency tracheostomy. Surgical goals should focus on complete extirpation of the mass, as residual tumor left behind during initial procedures is implicated in recurrence. Adjuvant chemotherapy is indicated in the treatment of histologically malignant tumors.

Oropharyngeal tumors with intracranial extension represent a more complicated clinical entity. Persistent patency of the craniopharyngeal canal during embryogenesis provides a means for direct extension of tumor from one cavity into the adjacent. The developmental phenomena surrounding the formation of this anatomical conduit have been well described.2 Some authors have reported gross and microscopic evidence of tissue connecting intracranial and extracranial regions of tumor through a patent canal.5, 10, 20

Prenatal and postpartum diagnostic tools in these complex cases remain constant: ultrasound and MRI are used to diagnose and define these tumors before and after birth. While the same principles of airway management and complete tumor resection apply, however, surgical planning must be tailored to each individual case. Consideration must be given to the morbidity associated with aggressive neurosurgical intervention in the neonate and to the need for coordination between craniofacial remodeling and skull base reconstruction.

Historically, reports in the English literature of teratomas involving both intracranial and extracranial spaces have been scarce, numbering 24. (Table 1) Ehrich's 5 review summarizes 6 such cases in the German literature prior to 1930 without presenting descriptions of pathological findings or patient outcomes. Hosoda10 cites no cases in the Japanese literature prior to his report.

The effects of oropharyngeal teratomas with intracranial extension upon the developing fetus are dependent upon their size and anatomical location. Tumors with massive intracranial components interfere with the development of the central nervous system and lead to fetal wasting. Oropharyngeal components may obliterate the fetal airway and further complicate neurological insults. Prognosis for newborns with extensive disease has traditionally been grim. Until the 1990s such lesions uniformly resulted in stillbirth or perinatal death. Ehrich, Vinters, Mamalis, and Rostad 5, 12, 15, 23 all described teratomas that filled the entire cranial cavities of stillborn fetuses. Duckett4 discussed a live birth with tumor filling the entire oral and nasopharyngeal cavities in addition to a 3-cm x 4-cm intracranial mass. Regular respiratory effort was never truly observed in the child, who died within one hour of delivery. Rostad 15 described an additional case of neonatal death within minutes of delivery where respirations were never established. The patient described by Hosoda 10 had oral and intracranial masses similar in location and dimension to those in Duckett's 4 report. The newborn died within 3 days. Fetal ultrasound examination in the cases reported by Smith 20 yielded prenatal evidence of significant intracranial disease associated with the tumors. One of these pregnancies was aborted while the product of the second died within one hour of birth.

Survival of varying duration in patients with more limited disease has been documented. As early as 1980 Whittle 25 attempted complete resection of a mature teratoma occupying the entire anterior cranial fossa, suprasellar area, left temporal lobe, and left orbit of a 10-week-old child. The child died 6 months after the operation with massive recurrence of tumor in the left orbit extensively invading the craniofacial skeleton. Of note was that pathological analysis of the recurrent tumor revealed the presence of an embryonal carcinoma. Arai 1 described a case of incomplete resection of an immature teratoma of the middle cranial, posterior cranial, and infratemporal fossae at 4 weeks of age. The patient died from tumor recurrence 7 weeks after surgery. By comparison, Arai, Ulreich, Gunkel, and Sarin 1, 9, 17, 22 reported more favorable results in children with subtotal resections of histologically mature teratomas. Tumor remnants were left behind in the parasellar area, cavernous sinus, suprasellar area, and middle cranial fossa, respectively. Follow-up of these patients has been limited, ranging from 4 days to 5 years, but suggests less aggressive behavior for these types of teratoma. Nevertheless, the potential for growth of residual tumor to cause morbidity or death in these cases is significant.

Complete resection of mature teratoma from the intracranial and extracranial cavities eliminates this risk and should be the guiding principle in the surgical management of these types of lesions. Advances in microsurgical approaches to the skull base and infratemporal fossa 7, 19 allow surgeons to more effectively target lesions in these areas with fewer complications. Long term disease-free survival following radical resection, however, has not yet been described in the literature. Of the two children who underwent perinatal resection and lived to at least 10 years of age, one became unilaterally blind following orbital exenteration 13 and the other had significant craniofacial deformity as well as developmental delay.6 Other descriptions of complete resection of mature teratoma describe varying degrees of esthetic and functional deficit. 6, 11 The risk of operative morbidity in these and all such cases is related to the anatomical position of the tumor and the nature and timing of craniofacial and skull base reconstruction.

The case we present is unique on several levels and highlights several salient features in the surgical management of this rare disease. Of all cases of oropharyngeal teratoma with intracranial extension described in the medical literature, our patient is the oldest survivor without evidence of recurrent disease, neurological deficiency, or craniofacial malformation. Nor has a delayed staged surgical approach to the orofacial and intracranial portions of the tumor, as employed in this case, been previously described. Arai and Lanzino 1, 11 described cystoperitoneal shunt placement prior to definitive tumor resection, but these initial procedures were palliative in nature. A second procedure to remove extracranial tumor remnants was conducted 4 days after the primary procedure in a case described by Ulreich.22 Description of the surgical indications and findings, however, was limited.

The rarity of cases of congenital teratoma characterized by both oropharyngeal and intracranial components coupled with the diversity of these tumors makes it difficult to detail standards of care in the surgical management of these patients. The appropriate timing of surgery as well as the surgical technique employed will vary with each individual child and the nature of each tumor encountered. In the case of our patient, perinatal resection of the extracranial component of the tumor removed the immediate threat to airway obstruction. Close subsequent monitoring of the residual intracranial tumor allowed surgery on a semi-elective basis. This was performed at an age where invasive surgery of the skull base would be better tolerated by the patient and technically less demanding than surgery on a neonate.

Such individual consideration must be applied to all cases of this complicated disease to maximize the likelihood of prolonged disease-free survival without complication.

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