Diagnosis.

In countries where prenatal ultrasonography (US) is not readily available, most SCTs are seen as a visible mass at birth, making the diagnosis obvious (Fig. 68-4). Prenatal diagnosis has important implications and will be discussed further.

There is an unexplained female preponderance of 3 : 1.34,65,67 The main differential diagnosis is meningocele. Typically, meningoceles occur cephalad to the sacrum and are covered by dura, but sometimes they are covered by skin. Examination of the child reveals bulging of the fontanelle with gentle pressure on a sacral meningocele, helping to establish the diagnosis before plain radiography, ultrasound, and magnetic resonance imaging (MRI) confirms it. The co-existence of meningocele with teratoma is well recognized in the familial form, but these are usually presacral. Rarely, a typical exophytic teratoma may have an intradural extension.68,69 Other lesions in the differential diagnosis of neonatal sacrococcygeal masses include lymphangiomas, lipomas, tail-like remnants (Fig. 68-5), meconium pseudocysts, rectal duplications, and several other rare conditions.^34,70–73

Although many neonates with SCTs do not have symptoms, some require intensive care because of prematurity, high-output cardiac failure, disseminated intravascular coagulation, and tumor rupture or bleeding within the tumor.74–78 Lethal hyperkalemia from tumor necrosis has also been described.⁷⁹ Lesions with a large intrapelvic component may cause urinary obstruction.^78,80 Besides looking for signs of a myelomeningocele, the physical examination should always include a rectal examination to evaluate for an intrapelvic component. The most helpful imaging studies consist of plain anteroposterior and lateral radiographs of the pelvis and spine, looking for calcifications in the tumor and for spinal defects, and ultrasound of the abdomen, pelvis, and spine. Further preoperative studies are unnecessary in most newborns.

The diagnosis of purely intrapelvic teratomas is often delayed.³⁴ Children develop constipation, urinary retention, an abdominal mass, or symptoms of malignancy, such as failure to thrive. Age is a predictor of malignancy in patients with testicular, mediastinal, and SCTs.² The risk of malignancy is less than 10% at birth, but rises to more than 75% after age 1 year for SCTs, with the exception of familial presacral teratomas. The risk of malignancy also is high for incompletely excised lesions. Complete excision of the tumor should be carried out as soon as the neonate is stable enough to undergo the operation. Serum markers should be determined before the operation for later comparison.

In recent decades, the diagnosis has often been made on prenatal ultrasound, especially when this examination is routinely performed in the second trimester. The site of the lesion, its complex appearance, and intrapelvic extension, with or without urinary tract obstruction, are easily recognized. Although most small teratomas do not adversely affect the fetus, the presence of a large solid vascular tumor is associated with a significant mortality rate, both in utero and perinatally.75,76,78,81–83 Perinatal mortality is usually related to prematurity or tumor rupture with exsanguination (or both). Premature delivery may occur spontaneously from polyhydramnios or may be induced urgently because of fetal distress or maternal pre-eclampsia.

Repeated ultrasound assessment of tumor size is important because the fetus should be delivered by cesarean section if the tumor is larger than 5 cm or larger than the fetal biparietal diameter.⁸⁴ Dystocia during vaginal delivery is associated with tumor rupture and hemorrhage, and is an avoidable obstetric complication. The options in managing unexpected cases with dystocia include emergency cesarean completion of the partially delivered fetus, who has been intubated and ventilated after vaginal presentation of the head.⁸⁴

Polyhydramnios with larger tumors may lead to premature labor; amnioreduction is often required to decrease uterine irritability.78,83 Tumors that are larger than the fetal biparietal diameter at diagnosis, or that grow faster than the fetus or grow faster than 150 mL/week, are associated with a poor prognosis.^82,85 As the tumor enlarges, the fetus may develop placentomegaly or hydrops, caused by high-output cardiac failure from vascular shunting within the tumor, with fetal anemia from intratumoral bleeding also playing a role. This is a harbinger of impending fetal death and should lead to urgent cesarean delivery, especially when the maternal mirror syndrome has developed.⁸⁶ Open fetal surgical excision/debulking is one option in fetuses considered too premature to deliver. It has been performed with success in three of eight cases in one center and in three of four cases in another.^76,87 Interestingly, there were no cases of fetal resection in the latter center in a more recent cohort of 23 fetuses with SCT, emphasizing that the indications for such a procedure are limited.⁸²

As a result of the maternal and fetal risks, less invasive therapeutic options have been sought. Successful intrauterine endoscopic laser ablation of the large feeding arteries has been described.⁸⁸ There have been several other reports, a few with good outcomes, but some with poor outcomes often related to severe fetal anemia and cardiac failure.^78,89,90 Alcohol injection has also been used.⁷⁸ Attempts at interrupting the high vascular flow have also been described by using radiofrequency ablation, with two survivors in the first four attempts.⁹¹ One survivor had significant perineal damage.⁹² As the technology has improved, there seems to be a renewed interest in this approach.^93–95 However, it remains unclear when early delivery is preferable to intervention in utero in fetuses with early hydrops and placentomegaly. Some advocate a fetal operation before 30 weeks of gestation,⁸² with the same group recently suggesting early delivery in selected fetuses after 27 weeks of gestation.⁹⁶ Others have reported survival after emergency delivery as early as 26 weeks of gestation.⁹⁷ The EXIT procedure (ex utero intrapartum treatment) has been used as an adjunct to allow safer resection of a ruptured teratoma in a 27 week gestation fetus, but long-term neurological sequelae were noted.⁹⁶

Purely cystic teratomas occur in 10–15% of cases. Prenatal diagnosis allows percutaneous aspiration to facilitate delivery (Fig. 68-6), to decrease uterine irritability, or to prevent tumor rupture at delivery.^{76,78,81,98,99} In another report, prenatal decompression using a cyst-amniotic shunt was successfully performed to relieve the obstructive uropathy caused by the cystic teratoma.¹⁰⁰ Fetal MRI is a useful adjunct to the prenatal evaluation, providing additional information that aids in counseling and preoperative planning.¹⁰¹ It also helps in the differential diagnosis when the teratoma is entirely presacral.¹⁰²

Operative Approach.

Adequate intravenous access, preferably in the upper extremities, and the availability of blood products should be ascertained before starting the operation, especially with large tumors.

For most tumors, the major component is extrapelvic and the patient is placed in the prone position. If a significant intrapelvic or intra-abdominal component is present, or if the tumor is highly vascular and bleeding within the tumor is suspected, it may be wise to begin with a laparotomy or laparoscopy (see above). Generally, most resections can be achieved completely in the prone position, especially if the internal portion is cystic (Fig. 68-7).⁷⁸ When in doubt, a safe approach is to prepare the skin from the lower chest to the toes, allowing the infant to be turned to the supine position without having to re-drape. Vaseline packing in the rectum facilitates its identification throughout the procedure. En bloc excision, including the coccyx, is preferable. Failure to remove the coccyx is associated with a high recurrence rate.^2,3,103 An acceptable gluteal crease and perineum is formed by the appropriate positioning of the perianal musculature. The use of plastic surgical principles to close the skin improves the cosmetic appearance of the scar (see Fig. 68-7, inset).¹⁰⁴

Although the chevron incision has been used by most surgeons, a vertical incision is sometimes advantageous. It is preferred for smaller teratomas because it leaves a nearly normal-looking median raphe (Fig. 68-8). Resection of the excess skin at the closure gives an optimal cosmetic result. Others have reported using this approach for large tumors as well.¹⁰⁵

Several techniques have been described to help in the management of giant SCTs. These include intraoperative snaring of the aorta,⁷⁷ laparoscopic division of the median sacral artery,^106,107 the use of extracorporeal membrane oxygenation and hypothermic perfusion,¹⁰⁸ devascularization and staged resection,^97,109 and preoperative embolization with or without radiofrequency ablation.^110,111 Autologous cord blood transfusion is another useful adjunct.¹¹²

Prognosis.

Fetuses with an SCT diagnosed in utero have a survival rate in excess of 90% if the tumor is small and discovered by routine prenatal ultrasound. If a complicated pregnancy is the indication for ultrasound evaluation, the mortality increases to 60%. Nearly 100% of patients die when hydrops or placentomegaly develop.76,78,81,113 Dystocia or tumor rupture during delivery are likely underreported as a cause of mortality.^83,114 In one series, 10% of babies died during transfer, all before the widespread use of antenatal ultrasound.¹¹⁵ In a report describing 24 patients with a SCT diagnosed on routine obstetric ultrasound, 3 were aborted electively, four died in utero at 20 to 27 weeks of gestation, and three died of tumor rupture during delivery at 29 to 35 weeks of gestation (one after vaginal and two after cesarean delivery).⁷⁵ The incidence of placentomegaly (none), hydrops (5%), and polyhydramnios (19%) was lower than in series in which ultrasound was performed for an obstetric reason.^76,84,116 Tumor size, vascularity, and content were used to develop a prognostic classification from a cohort of 44 fetal SCTs.¹¹⁷ Fifty per cent of infants with tumors 10 cm or greater that were highly vascular or fast growing died, whereas none died if these features were absent or if the tumor was predominantly cystic. Recently, a growth rate >150 mL/week was found to be associated with an increased risk of perinatal mortality.⁸² A vena cava diameter ≥6 mm and cardiac output ≥600 mL/kg/min have also been used to detect high-output cardiac failure in the early stages.⁸² Another prognostic classification involves the ratio of solid tumor volume over the head volume.¹¹⁸ In a series of 28 cases, none of the fetuses with STV/HV ratio <1 died, while 61% with a ratio >1 died. The same center has also reported risk stratification based on fetal echocardiographic findings.¹¹⁹ Finally, the ratio of tumor volume over fetal weight was found to be an early prognostic marker.¹²⁰

In the absence of severe prematurity and perinatal complications, the prognosis is dependent on the presence of malignancy and is therefore related to age at operation and completeness of resection.121,122 When the tumor is benign and completely excised, recurrence is low, unless the tumor is large and mostly solid.¹²³ The recurrent tumor may be benign or malignant, and benign metastatic tissue may become evident in lymph nodes.¹²⁴ Although immature or fetal elements in gonadal teratomas are associated with a higher risk of aggressive behavior, this is not considered true for SCTs.^2,5,16 However, a multicenter study identified immature histology, in addition to malignancy and incomplete resection, as risk factors for recurrence.¹²² Although malignant recurrence of a ‘benign’ teratoma may be as high as 10–15%,^6,122 the original benign diagnosis may have been due to sampling error,¹⁵ an undetected residual microscopic focus of malignant tumor,¹²⁵ or secondary to incomplete coccygectomy at the initial operation.³⁵ Patients whose tumors are resected after the newborn period have a higher risk of malignant recurrence, especially when an elevated AFP level is present at diagnosis. The elevated AFP likely signifies the presence of malignancy in the original tumor.^15,126 It is important to monitor all patients by physical examination, including rectal examination and serum markers (AFP and CA 125), every two or three months for at least 3 years because most recurrences occur within three years of operation.^24,127

Recurrent disease is usually local, but metastases to inguinal nodes, lung, liver, brain, and peritoneum can occur, including pseudomyxoma peritonei.¹²⁸ The prognosis of a malignant tumor or a malignant recurrence was dismal until the advent of platinum-based chemotherapy.¹²⁵ Survival rates of 80–90% are now achieved, even in the presence of metastatic disease, but the risk of late recurrences or second malignancies persists.^129–131 Older patients presenting with large malignant tumors usually undergo biopsy followed by chemotherapy before resection is attempted to avoid sacrificing vital structures.^16,130,132

A Children’s Cancer Group (CCG) review illustrates the shift in mortality causes, from late diagnosis/malignancy to perinatal events.¹²⁹ The mortality was 10% in 126 patients treated in 15 institutions from 1972 to 1994. Three patients died of severe associated anomalies. Two died of hemorrhagic shock postoperatively and six due to combinations of severe prematurity, birth asphyxia due to failed vaginal delivery, or preoperative tumor rupture. Death from a metastatic YST occurred in one patient. A second patient with metastatic disease was lost to follow-up and is presumed dead. Thus, only two deaths occurred from malignancy, despite a total of 20 YSTs (13 malignant at initial operation, seven malignant recurrences after resection of ‘benign’ teratomas). Owing to the effectiveness of current chemotherapy in treating recurrent disease, as well as its toxicity in young infants, it appears that a completely excised malignant YST does not require adjuvant therapy. These patients should be closely monitored clinically and with serial AFP measurements.¹³³ Similar encouraging results have been found in the German Cooperative Studies.¹³⁴

In the current era of the rather routine use of ultrasound in pregnancy, the prognosis for patients with an SCT is not dependent on Altman’s classification³⁴ but rather on tumor size, physiologic consequences, histology, and associated anomalies. The prognosis of malignant tumors depends on tumor type, stage, location, and patient age.¹²⁹ Functional results in survivors have been reported as excellent in most series.^78,135,136 However, several reports draw attention to fecal and urinary continence problems, as well as lower limb weakness.^{121,137–141} Some of these problems are clearly related to associated anomalies,¹¹⁵ the need for reoperation,¹⁴² or to the presence of large presacral or intra-abdominal tumors,^80,135 but they can occur after excision of purely extrapelvic benign tumors. A good outcome requires meticulous dissection along the tumor capsule, preservation and reconstruction of muscular structures, and long-term follow-up. One group advocates earlier cesarean delivery to minimize urologic sequelae in patients with large tumors causing urinary tract dilatation.¹³⁹ Others have placed vesico-amniotic shunts in such cases with good outcomes.78,100 Urodynamic studies and surveillance ultrasound are now being performed more regularly in some centers.¹⁴³ Patients with Currarino syndrome, who often have a tethered cord in addition to the presacral tumor, appear to have an increased risk of bladder and bowel dysfunction.^144,145 A poor cosmetic result was noted in more than half of the patients in another review.¹⁴⁶ These authors advocate early assessment of bladder, anorectal, and sexual function along with cosmetic results within a structured oncology follow-up program. The technique described by the Boston Children’s group is a major step to improve cosmesis (see Fig. 68-7),¹⁰⁴ while others favor a sagittal incision.¹⁰⁵

Mediastinal Teratomas.

Mediastinal teratomas are diagnosed from the fetal period to adolescence and even adulthood.2,147–149 Most are located in the anterior mediastinum, but a few have been described in the posterior mediastinum, some with epidural extension.^150–152 In infants, respiratory distress is a common presenting manifestation,¹⁵³ but in older children the teratoma is often an incidental finding on chest radiograph (Fig. 68-9).² Any patient with a mediastinal mass that presents with orthopnea or a reduction in the tracheal cross-sectional diameter of greater than 50% on axial imaging is at a significant risk for airway collapse during general anesthesia.¹⁵⁴ In these cases, procedures using local or regional anesthesia may be required to obtain a confirmatory diagnosis. Mediastinal teratomas may be first seen as a chest wall tumor and may even erode through the skin. They also can erode into a bronchus, with hemoptysis as the initial manifestation,¹⁵⁵ or rupture into the pleural cavity.¹⁵⁶ Secondary pericardial effusion and tamponade have also been described.¹⁵⁷ A strong association has been found with Klinefelter syndrome. In these cases, choriocarcinoma in the teratoma often leads to precocious puberty (see under Associated Anomalies).^2,25,58 Mediastinal germ cell tumors have also been observed concurrently or after treatment for hematologic malignancies such as Langerhan’s cell histiocytosis and hemophagocytic syndrome.^57,158,159 Histologically, the presence of immature tissue does not affect the prognosis in children younger than 15 years. After age 15, mediastinal teratomas have a high incidence of malignant behavior, which is usually indicated by elevated levels of AFP or β-hCG, or both.¹⁴⁹ For those with malignancy, YST is most prevalent in girls and young boys while mixed histology prevails in over 50% of older adolescent males.¹⁶⁰

Tumors should be excised through either a median sternotomy or a thoracotomy.16,161 Smaller tumors may be approached through an anterior mediastinotomy (see Fig. 68-9) or by thoracoscopy,¹⁶² although tumor seeding is a concern with the latter. Complete resection is the goal, but often these masses are too large at presentation and require initial biopsy followed by chemotherapy.^16,163,164 During chemotherapy, attention should be paid to the ‘growing teratoma syndrome’ that occurs when the benign elements within a germ cell tumor continue to grow.¹⁶⁵ A Pediatric Oncology Group (POG) and Children Cancer Group (CCG) intergroup study involving 38 patients demonstrated that primary resection could be achieved in 14 patients.¹⁶⁰ In another 18, chemotherapy reduced tumor size in 57% while the remainder were stable or increased in size. All patients with residual disease underwent successful post-chemotherapy resection. The overall survival for malignant mediastinal germ cell tumors was 71% which is less than for other extragonadal sites. The prognosis is best for young children with YSTs and worst in older adolescents with mixed germ cell histology.^149,160 In a recent series from Memorial Sloan-Kettering Cancer Center, normalization or reduction in preoperative tumor markers was the strongest predictor of increased survival.¹⁶¹

Intrapericardial Teratomas.

Intrapericardial teratomas are most commonly seen in the newborn period or in utero, with evidence of cardiorespiratory distress secondary to pericardial effusions or nonimmune fetal hydrops resulting from cardiac compression.2,3,166 While a fetal diagnosis allows for early postnatal treatment in most newborns, it may also offer an opportunity for antenatal interventions such as fetal pericardiocentesis.¹⁶⁷ Early delivery for emergency surgical excision should be considered if the baby develops signs of cardiac tamponade.¹⁶⁸ Intrapericardial teratomas are also the leading cause of massive pericardial effusion in the neonate and any delays in diagnosis could be fatal.^3,169 In older infants, it may present with respiratory distress or poor feeding. Ultrasound imaging usually demonstrates a cystic or solid teratoma located anterior to the right atrium and ventricle with attachments to the great vessels (see Fig. 25-4).¹⁷⁰ The tumor may also be found incidentally on chest radiographs performed for other reasons. The only treatment option for this lesion is excision. On histologic examination, these teratomas are usually composed of mature tissue with or without neuroglial elements.^2,3

Intracardiac Teratomas.

Intracardiac teratomas are rare and arise from the atrium or ventricle. Many can be cured by resection.¹⁷¹

Pulmonary Teratomas.

Few cases of intrapulmonary teratoma have been described.¹⁷² Symptoms include trichoptysis or hemoptysis. Lobectomy is the usual treatment.

Retroperitoneal Teratomas.

Retroperitoneal teratomas occur outside the pelvis, often in a suprarenal location. They represent about 4% of all childhood teratomas, and 75% occur in children younger than 5 years.3,173 They occur twice as frequently in females and may have an association with Klinefelter syndrome.^16,55