Sacrococcygeal teratoma

SACROCOCCYGEAL TERATOMA

 

diagram of SacrococcygealTeratomaClick To Enlarge

What is a sacrococcygeal teratoma (SCT)?

SCT is a tumor located at the superior portion of the buttocks which is comprised of different types of embryological tissue. The tumor usually has solid and cystic components and may be highly vascular. If diagnosed in the neonatal period, the vast majority of these tumors are benign; however, a few may be malignant. This tumor is very rare with an estimated occurrence between 1 in 35,000 and 1 in 40,000 live births. It is more common in females than males with a 4:1 ratio. The cause is unknown.

A SCT is classified based on its anatomic location. Type I identifies a tumor that is completely external. Type II tumors are external with a small internal portion located in the pelvis. Type III is a mixed tumor with an external portion and a larger internal portion extending into the abdomen. Type IV is completely internal.

What testing is recommended during pregnancy?

Serial ultrasounds will follow the growth of the SCT and the health of the baby. Some babies may develop polyhydramnios (excess amniotic fluid) which may lead to premature delivery. Doppler examination is performed to assess the degree of vascularity. Some highly vascular tumors create an arterio-venous shunt and lead to heart failure and the development of hydrops (generalized body swelling). Advanced hydrops may be associated with placentomegaly and maternal "mirror syndrome" in which the mother develops total body swelling. A fetal echocardiogram is recommended to assess the baby's heart function. In some cases, a fetal MRI is helpful in determining tumor size and anatomy.

Are there special considerations for the delivery?

The birth of the baby should be planned at a hospital that is prepared for high-risk deliveries, including pediatric surgical services and a neonatal intensive care unit. Premature delivery is more common among these babies often related to polyhydramnios and the tumor size. A Cesarean section is recommended for large tumors to prevent dystocia, tumor rupture, or bleeding.

Is there fetal treatment for sacrococcygeal teratoma?

Open fetal surgery has been reserved for babies with highly vascular SCT's who develop hydrops before 30 weeks gestation. There has been success removing the tumor before birth, which allows the baby's condition to improve and prolongs the length of the pregnancy. Minimally invasive fetal surgical techniques are being developed, but thus far have met with limited

success. Other options that may be available include removing some of the excess amniotic fluid around the baby.

What is the treatment for SCT?

Once the baby is stabilized, the tumor is surgically removed. The doctors will be monitoring your baby's heart function and blood pressure as large tumors contain a considerable amount of blood and vascular tumors can lead to heart failure. Once removed, the tumor will be sent to the pathology lab for analysis.

Are there other health problems that are more common among babies with SCT?

The long-term outlook for babies with SCT is usually very good. It is important to remember that even benign tumors may reoccur and the baby will require regular check-ups for at least 3 years. A blood test called a serum AFP (alpha-fetalprotein) will be scheduled routinely as a screening tool to identify tumor recurrence.

SCTs located mostly in the pelvis may affect the muscles and nerves in the pelvis, altering bowel and bladder function.

Can this happen again with another pregnancy?

There have been a few reported cases in families. Your doctor and a genetic counselor will review the risk in your family.

Synonyms: None.

Definition: Neoplasm composed of a wide diversity of tissues from all three germ cell layers foreign to the anatomic site in which it arises. It often occurs near the coccyx, where the greatest concentration of primitive cells exists for the longest period of time.

Prevalence: Most common tumor of the newborn period, with a prevalence of 0.25-0.28:10,000 live births; M:F 1:4 ratio.

Etiology: Assumed to be derived from the pleuripotent cells of Hensen"s node located anterior to the coccyx.

Pathogenesis: It is thought that the pleuripotential cell line escapes from the control of embryonic inducers and

organizers and differentiates into tissues not usually found in the sacrococcygeal region. The teratomas form and grow during intrauterine life, and can become quite large with the growth of most sacrococcygeal teratomas paralleling the growth of the fetus2.

Associated anomalies: Anomalies are more frequent than in the general population: 18% in infants with sacrococcygeal teratoma compared to 2.5% in the unselected population. No particular anomaly seems to be more frequently found than others. Reported organ systems involved include the musculoskeletal, renal, CNS, cardiac, and gastrointestinal tract3,4.

Differential diagnosis: Myelomeningoceles; also lipomas, hydromyelia, intracanalicular epidermoid tumors, dermal sinus stalks, extrarenal Wilms" tumors, retrorectal hamartomas, neuroblastoas, and pacinomas5.

Prognosis: Although the majority of these tumors are histologically benign, they are associated with significant morbidity and mortality due to secondary effects of the sacrococcygeal teratoma: prematurity of the infant, dystocia and traumatic delivery, exsanguination from hemorrhage into the tumor, or high output failure secondary to a steal phenomenon. The prognosis for cure is generally good after a successful complete removal of benign sacrococcygeal teratoma2.

Recurrence risk: The majority of tumors occur sporadically, but familial occurrence of presacral teratomas has been reported2.

Management: Before viability, the option of pregnancy termination should be offered to the parents. If the pregnancy is continued, management is based on fetal lung maturity and the presence or absence of placentomegaly and/or hydrops fetalis. Upon fetal lung maturity without placentomegaly and/or hydrops fetalis, elective early delivery by cesarean section is indicated. Placentomegaly and/or hydrops fetalis appears to be a preterminal event and requires emergency cesarean section or possible fetal surgical intervention4.

Introduction

Sacrococcygeal teratoma, although rare, is the most common tumor of the newborn, and has commonly been diagnosed at birth. With an increased utilization of ultrasonography, more sacrococcygeal teratomas are now discovered in utero. Prognostic differences exist when comparing fetal sacrococcygeal teratoma and neonatal sacrococcygeal teratoma. The neonatal prognosis is based on the American Academy of Pediatrics Surgical Section classification of sacrococcygeal teratoma by extension of tumor, whereas fetal prognosis appears to correlate inversely with tumor size, tumor growth rate, time of gestation at which the tumor becomes evident, and  the presence or absence of placentomegaly and/or hydrops fetalis6. We report 5 cases of sacrococcygeal teratoma diagnosed prenatally by ultrasound and their outcomes (Table 1).

Table 1: Outcome of five cases

Case reports

Case 1

A 29-year-old G2P1001 was referred for evaluation of uterine size greater than the dates at 24 weeks gestation. The ultrasound revealed a 13x10x11 cm sacral mass consistent with sacrococcygeal teratoma (fig. 1). Amniotic fluid was slightly increased.

On a repeat ultrasound at 27 weeks gestation, the mass had grown to 18x14x14 cm with low- level venous Doppler signal within the solid component (fig. 2). Hydramnios was present. In addition, the IVC was distended and cardiomegaly was noted (fig. 1-3). There was a small pericardial effusion, but no pleural effusion or ascites. The chest diameter was decreased. The fetus appeared to be male, but the scrotum was small. The impression was cardiac failure, apparent thoracic hypoplasia, and possible genital abnormalities. On physical exam, the patient had a slight cervical change, and thus was sent home on oral terbutaline and bed rest. The patient presented at 28 weeks

gestation with spontaneous rupture of membranes and premature labor. She was delivered by primary classical cesarean section secondary to the large size of the sacrococcygeal teratoma. A male was delivered with Apgars of 2 and 3. The newborn underwent an  emergency removal of the sacrococcygeal teratoma. The patient was lost to follow-up.

  Age in weeks at diagnosis

Sex Management

Case 1 24 Male Resection at birth.Case 2 12 Unknown D&C termination.Case 3 17 Female Prostin® terminationCase 4 32 Female Resection at birth.Case 5 20 Male Resection at birth.

Figure 1: Case #1: The heterogeneous caudal mass arising from the distal spine.

Figure 2: Case #1: Doppler velocimetry revealed minimal vascularity within the sacral mass.

Figure 3: Case #1: The right-sided cavities of the heart and the inferior vena are enlarged.

Case 2

A 26-year-old G1P0 was referred for evaluation after an abnormal ultrasound at 12 weeks gestation. The ultrasound revealed a large homogeneous solid mass appearing to arise from the fetal sacrum (fig. 4). No other structural abnormalities were identified within the limitations of a very early gestation. The mass was felt to be consistent with sacrococcygeal teratoma. The patient elected to terminate the pregnancy, and a D&C was performed.

Figure 4: Case #2: First trimester detection of a sacral mass.

Case 3

A 19-year-old G1P0 underwent routine ultrasound at 17 weeks gestation, which revealed a fetus with a large, complex sacrococcygeal mass measuring 6.5x4.7 cm consistent with a sacrococcygeal teratoma (fig. 5). Venous and arterial Doppler flow was noted. The amniotic fluid was normal. The patient underwent prostin termination at 19 weeks gestation. A live female was delivered with Apgars of 1 and 1, and was transferred to the NICU for

observation, where she expired shortly thereafter (fig. 6). An autopsy was performed (fig. 7). The 310g female fetus had a 7x7x3 cm soft sacrococcygeal mass with multiple fluid-filled cysts. On microscopic exam, the mass was shown to contain foci of respiratory epithelium, cartilage, gastrointestinal elements including glandular epithelium and immature liver parenchyma, and neuronal rosette formation. The tumor was benign. The fetus was also noted to have suffered an intracranial hemorrhage of the right lateral ventricle suspected to be secondary to “steal phenomenon” of  the tumor.

Figure 5:  Case #3:  Multiple echoes and cysts characteristic of a teratoma.

Figure 6: Case #3: X-ray of the fetus after delivery.

Figure 7: Case #3: The fetus at autopsy.

Case 4

A 20-year-old G4P3003 was referred at 32 weeks for a sacrococcygeal teratoma detected on ultrasound. The ultrasound examination revealed a rounded cystic mass projecting from the sacral region, measuring approximately 5x7 cm (fig. 8). Mature fetal lung indices were obtained from a 36 week amniocentesis, and an elective low transverse cesarean section

was performed. The patient delivered a female infant weighing 8 pounds with Apgars of 8 and 9. The infant was admitted to the NICU for observation and underwent resection of the sacrococcygeal teratoma. A 6x8 cm cystic pedunculated mass was removed en bloc with the coccyx. Good cosmetic results with no complications were achieved.

Figure 8: Case #4: Longitudinal view of sacrococcygeal mass.

Case 5

A 26-year-old G2P1, who underwent an ultrasound at 20 weeks gestation suggestive of a 6 cm sacral mass with normal cranial and vertebral findings, was referred for further evaluation (fig. 9-10). Repeat sonography demonstrated a large 10 cm heterogeneous sacrococcygeal teratoma. Doppler flow studies indicated minimal blood supply and an abnormal umbilical artery S/D ratio of 5.14. The inferior vena cava and heart were enlarged. The patient proceeded with the pregnancy and underwent elective low-vertical cesarean section at 35 weeks. A male weighing 3105g with Apgars of 8 and 9 was admitted to the NICU. The infant"s complex pedunculated tumor arising from the coccyx and the right buttock was resected the next

day (fig. 11-12). The gluteal muscles were distorted and the tumor was adherent to the ischium. Branches of the sciatic nerve were sacrificed to achieve a complete resection.

 

Figure 9: Case #5:  Longitudinal and caudal views of complex sacral mass.

Figure 10: Case #5: Longitudinal view of lumbosacral spine reveals an intact neural tube, differentiating the teratoma from a complicatedmeningomyclocele.

Figure 11: Case #5: Caudal view at delivery.

Figure 12: Case #5: The complexity of the teratoma is appreciated prior to surgical resection.  The primary mass originated from theischium while the pedunculated aspect originated from the coccyx.

Discussion

Definition

Sacrococcygeal teratoma is a congenital germ cell tumor arising in the presacral areas, and is the most common tumor of the newborn period. This usually benign tumor is composed of a wide diversity of tissue foreign to the sacrum and contains all three germ cell layers. Neuroglias are the most common histologic finding in sacrococcygeal teratoma7. The tumors are subdivided and classified according to their location:

·        Type I - tumors predominantly external with only minimal presacral involvement;

·        Type II - tumors presenting externally but with a significant intrapelvic extension;

·        Type III - tumors apparent externally but with predominant pelvic mass and extending into abdomen;

·        Type IV - Presacral with no external presentation3.

Pathogenesis

Sacrococcygeal teratomas arise from the primitive knot or Hensen"s node. Hensen"s node is an aggregation of totipotential cells that are the primary organizers of embryonic development. Originally located in the posterior portion of the embryo, it migrates caudally during the first weeks of life inside the tail of the embryo, finally resting anterior to the coccyx. Segregation of totipotential cells from Hensen"s node probably gives rise to sacrococcygeal teratomas8. These pleuripotential cells escape from the control of embryonic inducers and organizers and differentiate into tissues not usually found in the sacrococcygeal region2. The tumor occurs near the coccyx, where the greatest concentration of primitive cells exists for the longest period of time during development.

Prenatal diagnosis

The most common prenatal presentation of sacrococcygeal teratoma is uterus size greater than dates5.  However, the majority of cases usually manifest no clinical symptoms during pregnancy, and with the increasing frequency of routine ultrasound during pregnancy, more incidental findings of these tumors will occur. The differential

diagnosis of sacrococcygeal teratomas include myelo-meningoceles, lipomas, hydromyelia, intracanalicular epidermoid tumors, dermal sinus stalks, extrarenal Wilms" tumors, retrorectal hamartomas, neuroblastomas, and pacinomas4. Excluding meningomyelocele and twin fetuses, a mass attached to the fetal rump is most likely a teratoma6. A sacrococcygeal teratoma can be distinguished from its primary differential meningomyelocele by its more abundant internal soft tissue, whereas the meningocele is more completely cystic in nature9. alpha-Fetoprotein can be normal or elevated in sacrococcygeal teratomas but sonography can distinguish these lesions from neural tube defects10. Early prenatal sonographic detection of sacrococcygeal teratoma allows for optimal perinatal obstetric and surgical management.

Management and prognosis

Neonatal sacrococcygeal teratoma is a well-defined entity. The natural history of fetal sacrococcygeal teratoma is not so well defined, and although the American Academy of Pediatrics Surgical Section clinical classification is an important prognostic indicator in neonatal sacrococcygeal teratoma, it does not appear to predict outcomes in fetal sacrococcygeal teratoma11. If the diagnosis of sacrococcygeal teratoma is made early enough in gestation and if any poor prognostic factors such as oligohydramnios, severe renal anomalies, or marked hydrops are present, elective termination of pregnancy may be considered for sacrococcygeal teratoma2. Most fetal teratomas can be managed by planned delivery and postnatal surgery. Holzgreve et al have described an algorithm to approach the management of sacrococcygeal

teratoma based on fetal lung maturity and the presence or absence of placentomegaly and/or hydrops fetalis (Table 2 )5. In the absence of placentomegaly and hydrops, the fetus should be followed by serial ultrasound until fetal pulmonary maturity is adequate for survival. The patient should then undergo elective early delivery by cesarean section to avoid trauma to the mass or dystocia.

The occurrence of placentomegaly and/or hydrops fetalis appears to be a preterminal event indicating imminent fetal demise. Its occurrence in a fetus with adequate pulmonary maturity demands emergency cesarean section. Fetuses developing placentomegaly and/or fetal hydrops prior to adequate lung maturity are the most difficult management decisions. These fetuses may be candidates for transfusion or fetal surgical intervention5.

It is important to predict early after diagnosis which fetuses will survive and which will develop hydrops and die. Measurement of fetal aortic blood flow and cardiac output with a Doppler probe may be used to follow the development of high-output cardiac failure before the appearance of fetal hydrops and might potentially be used to predict outcome12.

Prognosis of sacrococcygeal teratoma is improving due to prenatal detection, planned intrapartum management, and prompt surgical resection13. The optimal outcome for fetal sacrococcygeal teratoma requires better understanding of its unique natural history and the perfection of monitoring and fetal intervention.

Table 2: Management of fetuses with sacrococcygeal teratoma 5

Immature lungsNo placentomegaly or hydropsPlacentomegaly or hydrops

Mature lungsNo placentomegaly or hydrops

Serial USLarge or symptomatic tumor

Small or asymptomatic tumorTermination of pregnancy or fetal surgery

Elective cesarean deliveryTerm vaginal delivery

Emergency cesarean delivery

 Prognosis�Long term survival of newborns with SCT isgenerally excellent (92-95%)�

Surgical mortalities are usually related tocoincidental birth anomalies or tohaemor rhagedur ing su rgery�Generally:Benign-Disease free survival is > 90%Malignant-Significant mortality

 

Diagnosis: Sacrococcygeal teratoma

Discussion:

Definition: Neoplasm composed of a wide diversity of tissues from all three germ cell layers foreign to the

anatomic site in which it arises. It often occurs near the coccyx, where the greatest concentration of primitive cells exists for the longest period of time.

The tumors are subdivided and classified according to their location:

�������� Type I - tumors predominantly external with only minimal presacral involvement;

�������� Type II - tumors presenting externally but with a significant intrapelvic extension;

�������� Type III - tumors apparent externally but with predominant pelvic mass and extending into abdomen;

�������� Type IV - Presacral with no external presentation.

Prevalence: Most common tumor of the newborn period, with a prevalence of 0.25-0.28:10,000 live births; M:F 1:4 ratio.

Etiology: Assumed to be derived from the pleuripotent cells of Hensen"s node located anterior to the coccyx.

Pathogenesis: It is thought that the pleuripotential cell line escapes from the control of embryonic inducers and organizers and differentiates into tissues not usually found in the sacrococcygeal region. The teratomas form and grow during intrauterine life,

and can become quite large with the growth of most sacrococcygeal teratomas paralleling the growth of the fetus.

Associated anomalies: Anomalies are more frequent than in the general population: 18% in infants with sacrococcygeal teratoma compared to 2.5% in the unselected population. No particular anomaly seems to be more frequently found than others. Reported organ systems involved include the musculoskeletal, renal, CNS, cardiac, and gastrointestinal tract.

Prognosis: Although the majority of these tumors are histologically benign, they are associated with significant morbidity and mortality due to secondary effects of the sacrococcygeal teratoma: prematurity of the infant, dystocia and traumatic delivery, exsanguination from hemorrhage into the tumor, or high output failure secondary to a steal phenomenon. The prognosis for cure is generally good after a successful complete removal of benign sacrococcygeal teratoma.

Recurrence risk: The majority of tumors occur sporadically, but familial occurrence of presacral teratomas has been reported.

Sacrococcygeal teratoma is a rare tumor of infancy occurring approximately once in every 40,000 births, but its presentation is frequently striking. Early and carefully considered

management is essential for successful treatment. An overwhelming female preponderance has been repeatedly confirmed in all large series: 75 to 85 percent of the tumors occur in females. A 50 percent incidence of multiple births in families of children with sacrococcygeal teratoma cited by some authors is probably excessive, but in most series an increased incidence of multiple births is noted.

The etiology or embryonic explanation for the occurrence of sacrococcygeal teratoma is not clear. The sacrococcygeal region is the most common site of occurrence of teratomas in infants and children, the second most common being the gonads. Origin of the tumor is usually ascribed to the totipotential cells of the primitive knot or Hensen's node, embryonic entities that contribute to the gonadal ridge and eventually end up in the coccygeal region.

The female preponderance is explained by the later differentiation of the totipotential cells into germ cells in the female, thus allowing more time for neoplastic changes than in the male. Another theory suggests that the teratoma is an abortive attempt at twinning. Occasionally, tumors in the sacrococcygeal area have well-defined body parts and suggest an incomplete conjoined twin.

Clinical Presentation

Most sacrococcygeal teratomas present at birth as sizable masses extending outward from the sacrum and coccyx with varying degrees of involvement of one or both buttocks. They may be solid or cystic: most are a mixture of the two. The composition of the mass does not help in deciding its benign or malignant potential. Many (15 to 45 percent) have significant intrapelvic or presacral components as well, and approximately 10 percent are entirely intrapelvic and can only be identified on rectal examination. Altman et al. in surveying 398 cases of sacrococcygeal teratoma from the Surgical Section of the American Academy of Pediatrics in 1973 divided the tumor into four types. Type I. primarily external with minimal presacral component (47 percent). Type II. presenting externally, but with a significant presacral component (35 percent). Type III. tumor apparent externally, but the predominant mass is pelvic with abdominal extension (9 percent). Type IV. presacral without an external component (10 percent). The presacral tumors are of the most interest and importance to the neurosurgeon because it is the dysraphic anomalies that may

present in the same area. The externally presenting sacrococcygeal teratoma is usually such an obvious tumor mass and it attaches so much lower than a lumbosacral myelomeningocele that only rarely is it difficult to differentiate the two.

With increasing use of maternal - fetal sonography, an entirely new presentation of sacrococcygeal teratoma has been recognized: the fetus with a rapidly enlarging sacrococcygeal teratoma that may develop fetal hydrops. Placentamegaly, polyhydramnios, a preeclampsia-like syndrome, and/or premature labor may develop in the mother. Initially, the mortality for this group of infants was very high: many died in utero. Of those born alive, most were markedly premature and suffered from respiratory distress syndrome. Langer et al. postulated that this syndrome resulted from high-output cardiac failure caused by arteriovenous shunting through the tumor. They suggested the use of the Doppler probe to measure descending aortic blood flow and recognize highoutput demands before fetal hydrops develops. They demonstrated reversal of the hydrops by fetal surgical excision of the mass at 24 weeks' gestation, but premature labor resulted in a nonviable fetus.

In a related publication. researchers in the same laboratory demonstrated markedly increased flow in the descending aorta and initially in the placenta of an infant with a large sacrococcygeal teratoma. Combined ventricular output was over twice the normal, and the cardiac ventricles were enlarged more than two standard deviations from the normal. Initially increased placental flow gradually decreased below normal as more and more of the cardiac output passed through the enlarging tumor. Despite good contractility, the fetal heart could not cope with the increased demand, and fetal hydrops resulted.

Nakayama et al. reported survival in two infants born with large sacrococcygeal teratomas with renal failure and respiratory distress. They suggested that fetal surgery should be considered only if severe hydrops develops before 28 to 30 weeks' gestation. They postulated that the tumor added a large amount of de saturated blood to the mixed venous return, resulting in decreased oxygen saturation, pulmonary vasoconstriction, pulmonary hypertension and right-to-left shunting. In addition they suggested that ascites, anasarca, and the intravascular volume of the tumor represent grossly exaggerated fluid

compartments that alter respiratory and renal function. Early excision of the tumor reversed these abnormalities in their infants.

With in utero diagnosis of sacrococcygeal teratoma, rapidly enlarging tumors that may result in fetal hydrops can be recognized and monitored; infants with large tumors should be delivered early by cesarean section. Presacral teratomas can be recognized early. Since these tumors have had the highest incidence of malignancy, the question of whether or not they are malignant from the onset or become so with delay in recognition and treatment may be resolved in the future. Additionally, infants with sacrococcygeal teratoma and associated spinal dysraphism can be recognized.

The majority of sacrococcygeal teratomas are asymptomatic masses. Occasionally, trauma during delivery results in rupture or severe hemorrhage. Coagulopathy has been recognized, especially in association with large tumors in premature infants. Although hemorrhage may occur into these large tumors in utero. this was not a necessary prerequisite for a coagulopathy developing postnatally. Coagulopathy developed in the same patient population as did fetal hydrops, and Murphy et al. postulate that the arteriovenous fistula formation within the large tumor may result in a "steal syndrome" that may cause stasis within the tumor and consumptive coagulopathy. Additionally, the large surface area of defective endothelium within the vascular bed of the tumor may initiate disseminated intravascular coagulopathy.

When the presacral component is significant, urinary tract and gastrointestinal tract obstruction may result. Most of these infants have at least some degree of obstructive uropathy and constipation may be the presenting complaint of infants with an entirely presacral sacrococcygeal teratoma. Dunnellon and Swenson maintain that significant obstructive symptoms occur only in malignant tumors. Others do not substantiate this finding.

Associated congenital anomalies and second tumors are infrequent. Usually spinal dysraphism is not a consideration in these patients. However, several authors including Moazam, Talbert, Ashcraft and Holder have reported series of presacral teratomas associated with anorectal anomalies, most often anal stenosis. A triad of anorectal anomalies, anterior meningocele and

presacral teratoma has been reported. Ashcraft and Holder's report documents the familial nature of this triad with 17 patients in 6 kindreds. Altman reported an 18 percent incidence of associated anomalies, mostly musculoskeletal, in the 398 patients in the American Academy of Pediatrics series. Although highly unusual, occasional reports of delay in diagnosis until adulthood can be found in the literature.

Differential Diagnosis

The externally presenting sacrococcygeal teratoma must be distinguished from a lipoma and a low myelomeningocele. The lipoma is generally a more uniform and homogenous mass than is the sacrococcygeal teratoma and is frequently associated with a capillary hemangioma in the overlying skin. The absence of the usual dermal defect and the intact sacral spine rule against myelomeningocele.

Sacrococcygeal teratomas that are entirely presacral and many that are partly presacral are unfortunately seldom discovered in early infancy, the frequent failure of the primary care physician to perform a good rectal examination on infants is one reason for this. The tumor presents later in infancy with constipation, urinary tract infection secondary to obstructive uropathy or occasionally with perineal or rectal pain. The presacral mass must be differentiated from an anterior meningocele, rectal duplication, retrorectal abscess and other tumors, particularly neuroblastoma. An anterior meningocele will often collapse with digital pressure. and the spinal defect can be confirmed by sacral spine films. Neural crest tumors are frequently associated with elevations of catecholamine degradation products such as urinary vanillylmandelic acid (VMA), but occasionally histopathological evaluation is the final arbiter. Calcification may be present in sacrococcygeal teratomas and neuroblastomas, but gross areas of calcification usually suggest a sacrococcygeal teratoma and rule against pararectal abscess. In the absence of obvious signs of infection, one should refrain from the diagnosis of an abscess in the face of a presacral mass.

Pathology

Sacrococcygeal teratoma is a true teratoma: this usually implies that elements of all three primitive germ cell layers are present. However, Dehner describes teratomas as having one or more

somatic tissues in haphazard arrangement with little evidence of organization. It is not necessary to have elements from all three embryonic layers for diagnosis. He cites Gonzalez-Cruissi: teratomas are neoplasms that originate in pluripotent cells and are composed of a wide diversity of tissues foreign to the organ or anatomic site in which they arise. Willis has similarly described them: .. A true tumor or neoplasm composed of multiple tissues of kinds foreign to the part in which it arises.

Teratomas may arise from primordial germ cells or from the yolk sac itself. 45 to 48 percent occur as sacrococcygeal teratomas. The tumors are usually a mixture of solid and cystic elements. Although the frankly malignant tumors are often more solid, a grossly cystic appearance cannot be depended upon to rule out malignant elements.

Actual organ formation has rarely been described, but tissues from any organ in the body may be found in these tumors when they are composed of mature adult tissue. Large portions of these tumors often contain neural elements. Donnellan and Swenson, Dehner and Ravitch have described the histopathology extensively.

Malignant versus Benign Tumors

Sacrococcygeal teratoma presents in three distinct forms: (1) entirely mature adult-type tissue. which is clearly benign: (2) a mixture of mature and embryonic tissues, the latter often being of neural or endodermal sinus (yolk sac) origin and haying a malignant potential: (3) tumors consisting in part or entirely of frankly malignant tissue. Woolley has found 51 percent benign. 21 percent embryonic and 28 percent frankly malignant tissue in a series of 57 cases of sacrococcygeal teratoma. Dehner reports similar ranges with 60 to 70 percent mature and clearly benign: 10 to 15 percent with immature elements without frank malignancy: and 15 to 30 percent malignant. Most series report an overall malignancy rate of about 25 to 30 percent.

The malignant tissues are most frequently embryonal carcinoma, often of endodermal sinus origin, but neural tumors including neuroblastoma as well as adenocarcinoma have also been described. In the newborn and early infancy period (up to 2 months of age) only 7 to 10 percent of the tumors are malignant or result in malignant consequences after complete removal, although Mahour et al. found 7 malignant tumors

among 33 neonates (2 I percent). In the AAP Surgical Section survey in 1974, Altman et al. reported a 17 percent overall malignancy rate. Under two months of age. 7 percent of the tumors in females and 10 percent of those in males were malignant. Over two months of age at diagnosis. the malignancy rate soared to 50 percent in females and 67 percent in males.

In updating the Los Angeles Children's Hospital series in 1988, Mahour reported 68 patients with sacrococcygeal teratoma. Twenty-one (31 percent) of the tumors were malignant. Of these 21 patients, 16 had died of their tumor.

Hawkins et al. in reviewing a series of 89 nongerminomatous malignant tumors from the Paediatric Oncology Group. found 26 children with malignant sacrococcygeal teratoma. Fifteen were pure yolk sac tumors and 11 were mixed yolk sac tumors and teratomas. Of note are five of the patients who presented under one month of age. Four of the tumors were resected, but only one patient had a coccygectomy: the fifth child underwent biopsy only. All five developed recurrence with malignant yolk sac tumors within 31 months of the initial resection or biopsy. Only the child who had undergone initial coccygectomy survived after reresection.

The longer the tumor remains beyond early infancy, the higher the incidence of malignant complications, so that by a year of age well over 50 percent are frankly malignant. In one series. 22 of 24 tumors in infants over 2 months of age were malignant.

Possibly the embryonic tissue of the tumors that are not frankly malignant at birth degenerates into invasive malignant tissue with time. However. since a large percentage of the malignant tumors are among those with a significant intrapelvic component and these tumors are notoriously discovered later in infancy, it may be that many of these were malignant from the outset. Donnellan and Swenson have found that 33 percent of tumors noted at birth were malignant when removed after 4 months of age. The intrapelvic tumor must be considered to be malignant until proved benign histopathologically.

Alphafetoprotein may provide a useful marker for sacrococcygeal teratoma because a large percentage of the malignant tumors are thought to be of endodermal sinus tract (yolk sac) origin. However, alphafetoprotein has not been a

consistently dependable marker for sacrococcygeal teratoma. It seems to be useful as a marker for recurrence of yolk sac tumors. Although oncofetal antigens (Alphafetoprotein, carcinoembryonic antigen, and human chorionic gonadotrophin) can be found in the tissues of sacrococcygeal teratomas, their levels in the amniotic fluid have not correlated well with tumor stage. One patient with a sacrococcygeal teratoma associated with spina bifida showed no elevation of Alphafetoprotein levels in the amniotic fluid. Finally, an interesting observation is that the female predominance may not be found in the malignant tumors.

Treatment

The ideal treatment for sacrococcygeal teratoma is complete excision in the newborn period. This can be done through either a chenon-shaped transverse incision placed between the coccyx and anus or through a midline incision extending from the lower sacrum to just proximal to the anus. Technical considerations include packing the anus to aid in identification, careful blunt dissection on the tumor capsule to preserve splayed out elevator ani fibers that will usually recover and assure fecal continence. careful dissection to identify the blood supply extending down from the spinal arteries and complete excision of the coccyx. The latter is essential if recurrence is to be avoided. keeping in mind that it is the most malignant elements that usually recur: benign tumors have also recurred when the coccyx has been retained. None of 51 benign tumors in which the coccyx was removed recurred in the Donnellan and Swenson series. However, Dehner states that there have been occasional cases of sacrococcygeal teratoma with all mature elements completely excised with coccygectomy in the neonatal period that have recurred as endodermal sinus tumors at one year of age. This is substantiated in the series presented by Schropp et al. In addition, several tumors with immature elements that were completely excised have recurred.

Even those tumors with significant presacral, intrapelvic or "abdominal" extensions can usually be removed from below by blunt dissection since the only really firm attachment of the benign tumors is to the coccyx. One should not hesitate to add an abdominal approach if this proves necessary. Obviously invasive malignant tumors cannot be removed so easily. With careful technique, it should be possible to remove most

of these tumors without rupture. with minimal blood loss and without injury to normal structures.

The muscle can be reconstructed by suturing to the sacral periosteum and closing the retrorectal space. Suction drainage of the retrorectal and subcutaneous tissues avoids haematoma or seroma formation and reduces the risk of infection. When the tumor is very large, the skin flaps may need to be trimmed for a better fit .

Until the 1980s, patients with malignant tumor elements whose tumors could not be completely excised and patients with malignant recurrences or metastases faced an overwhelming mortality. Adjuvant chemotherapy did not seem to play much of a role in salvaging these patients. The usual regimens utilized were variations of drugs used for the treatment of Wilms tumor and neuroblastoma. These included vincristine, dactinomycin and cyclophosphamide. The use of multi-agent chemotherapy consisting of combinations of cisplatinum (cisplatin), bleomycin, vinblastine or etoposide (VP-16) have shown encouraging results with a majority of patients surviving. Radiation therapy has been added in some series, but its role has not been well defined.

Results

When the tumor is completely removed in the neonatal period, recurrence is rare, and only the occasional unfortunate infant who already has an invasive malignant tumor will die of recurrence or metastatic disease, especially now that multiagent chemotherapy seems to be efficacious for malignant sacrococcygeal teratoma. Those cured infants should be functionally intact as well.

Havránek et al. reported late functional results in a series from Sweden. Twenty-five of 34 patients were available for follow-up. Fifteen had normal bowel habits: ten were soiling, but four of these were less than 3 years old. Twenty-one had normal micturition: four showed urinary incontinence, two requiring clean intermittent catheterization. There was no difference between tumors that were completely external (type l) versus those that were partially or largely intrapelvic (types III and IV). The authors question whether the functional deficits resulted from the tumors or the operative procedures.

In contrast. Bass et al. reported 49 cases with 10 deaths and long-term follow-up of 25 patients. all

of whom were continent of urine and stool: Ten were troubled with constipation and five had had urinary tract infections. Finally, Lahdenne et al. looked at late urologic sequelae in 45 of 70 original patients. 57 of whom were still alive. Thirty-five had abnormal urine flow on uroflometry: eight were symptomatic. Twenty-seven showed slow bladder emptying, increased capacity or increased residual urine volume. In 8 patients with significant intrapelvic extension of the tumor, bladder emptying was poor: however, 8 of the 35 patients also had spina bifida occulta: six at S 1. one at L5-S 1. and one at L4-S1. Four others had anatomic urinary tract anomalies.

The greater the length of time after 1 to 2 months of age that the tumor remains, the higher the incidence of malignant change. Few malignant tumors that are not completely excised are likely to be cured by surgery alone and even those patients with malignancy that have their tumors seemingly completely excised, are rarely permanently cured. In 1981 Raney et al. stated that nearly every patient with malignant sacrococcygeal teratoma who develops recurrent disease will die, usually within one year of initial diagnosis.

In 1984 Beddis et al. reported two cases of disseminated malignant sacrococcygeal teratoma treated with cisplatin, vinblastine. and bleomycin who were free of disease and had normal Alphafetoprotein levels 18 and 30 months following treatment. Their choice of these agents was based on the yolk sac origin of the malignant elements.

In 1989 Diez and Richard compared 10 patients treated earlier with surgical excision, radiation therapy and a combination of methotrexate, dactinomycin and cyclophosphamide with a more recent series of 15 patients treated with vincristine, dactinomycin, cyclophosphamide, doxorubicin, bleomycin and cisplatin. Only one patient of the earlier series survived. while 7 of the 15 in the later series were alive and free of disease. Two of the eight patients in the later series died of toxicity, but were free of tumor. Shanbhogue et al. reported a series of 15 malignant sacrococcygeal teratomas treated from 1954- to 1985. Six patients treated prior to 1970 received no chemotherapy: their median survival was two months. Some encouragement was noted in five patients treated between 1971 and 1979. All received vincristine, dactinomycin and cyclophosphamide: three received radiation

therapy. Median survival was 11 months. Four patients were treated after 1980 with more aggressive chemotherapy regimens consisting of vincristine, dactinomycin, cyclophosphamide and adriamycin in one patient and cisplatin, bleomycin and VP-16 (etoposide) in three patients: all were alive a median of 27 months (range 15 to 96 months) when the series was reported in 1989.

Pinkerton et al. substituted carboplatin for cisplatin in their series of malignant germ cell tumors in an effort to reduce the renal and auditory toxicity of cisplatin. Four of the 21 tumors were sacrococcygeal teratomas. Two of the four relapsed: these were two-thirds of the relapses in the whole series.

Later reports (1992) document two series of patients treated successfully with adjuvant chemotherapy. Of eleven patients with malignancies treated by Havránek et al., one who died was treated with a single agent: ten were treated with multiple agent chemotherapy and eight with cisplatin, bleomycin and vinblastine. Eight are alive and tumor-free after1 to 9 years: two late relapses were treated with excision and had survived to the time of the report.

Schropp et al. reported 16 children with malignant sacrococcygeal teratomas among 73 patients treated over a 40 year span. Long-term survival was achieved in 7 of the 16. Since 1976. only 2 of 10 patients underwent multiagent chemotherapy and/or radiation therapy died of their disease. In addition, there were five recurrences among 57 patients whose tumors originally were thought to be benign. One of these that had immature elements initially recurred three times and was found to have embryonal carcinoma metastatic to lymph nodes.

Now that multimodal therapy is providing effective in patients with sacrococcygeal teratomas with malignant elements who previously would have died of their disease, it will become important to define the role of multi modal therapy for each individual patient. It will be essential to determine whether or not patients with clearly malignant tumor elements that are completely excised should haw multimodal treatment initially as adjuvant prophylactic chemotherapy or whether recurrence or metastasis can be awaited. An important and as yet unanswered question is whether adjuvant chemotherapy is indicated for infants with immature tumor elements when the tumor is

completely excised. The incidence of malignant recurrence in such tumors needs to be clarified. Those chemotherapeutic agents that have been successful in curing malignancies associated with sacrococcygeal teratoma have significant toxicities. and a few children have died of the complications of the chemotherapy. Nevertheless, the future for those children with malignant tumor elements is much brighter since the demonstration that appropriately chosen chemotherapeutic agents can control the malignant elements and result in long-term survival.

Teratoma - description

Embryonal neoplasm containing tissue derived

from all 3 germ layers (endoderm, mesoderm,

and ectoderm):

Mature or immature and may occur with or without associated malignant elements

A subset of the broader class of germ cell tumors

Teratoma - general prevention

There is no known prevention for the

development of teratomas and other germ

cell tumors.

Teratoma - epidemiology

Gonadal and extragonadal germ cell tumors account for ~3% of childhood malignancies (<15 years) and 15% of malignancies of ages 15–19 years.

Incidence of germ cell tumors as a whole is ~2.5 cases per million in white children

and 3 cases per million in black children <15 years of age.

Boys and girls are equally affected.

One suggestive epidemiologic association is with high maternal hormone levels during pregnancy.

More controversial associations include younger gestational age; viral infections including herpes simplex virus, varicella-zoster virus, cytomegalovirus, mumps; other congenital anomalies; maternal urinary tract infection or tuberculosis; and paternal occupation in chemical industries.

Sacrococcygeal teratoma: Accounts for 40% of all childhood germ cell tumors and up to 78% of extragonadal germ cell tumors. Most prevalent in infants; girls more frequently affected

Testicular and ovarian tumors: Most prevalent in infants and adolescents

Vaginal tumors: Most prevalent in girls <3 years old

Mediastinal tumors: Average age of the pediatric patient is 3 years, but also found in adolescents; most common extragonadal germ cell tumor in adults

Teratoma - risk factors

Teratoma - genetics

Most consistent (80% of germ cell tumors) structural chromosomal abnormality is an isochromosome 12p [i(12p)].

No pattern of inheritance is known.

Teratoma - pathophysiology

Absence of normal mitotic/meiotic arrest of primordial germ cells in gonads leading to gonadal tumor formation. Aberrant migration of primordial germ cells during embryonal development, causing germ cells to come to rest outside the gonads leading to extragonadal tumors.

Mature teratoma: Contains well-differentiated, nonmitotic tissues from all 3 germ layers, such as squamous epithelium, neuronal tissue, muscle, teeth, cartilage, bone, GI, and respiratory epithelium.

Immature teratoma: Contains various immature tissues representative of all 3 germ layers; divided histologically into 4 grades, 0–3, dependent on degree of immaturity and mitotic activity

Teratoma with malignant germ cell elements: Foci of malignant tissue that resemble other germ cell tumors such as embryonal carcinoma, yolk sac tumor (endodermal sinus tumor), and choriocarcinoma, in addition to mature or immature tissues

Teratoma - DIAGNOSIS

Teratoma - signs & symptoms

Teratoma - history

External mass, constipation, urinary abnormalities, lower extremity weakness:

o Sacrococcygeal mass may impinge on nerve structures.

o Anterior sacrococcygeal mass may have no external component.

o Fetal sacrococcygeal teratoma often initially picked up on prenatal sonography.

Cough, wheeze, dyspnea, hemoptysis, superior vena cava syndrome: Suggest anterior mediastinal mass

Blood-tinged vaginal discharge: Vaginal teratoma

Abdominal pain, nausea, vomiting, constipation, urinary tract symptoms: Ovarian tumors present late with a large mass. Symptoms mimicking acute abdomen may indicate ovarian torsion.

Painless scrotal swelling or painful testicular torsion: Testicular mass may be teratoma.

Cryptorchidism: Associated with germ cell tumors in boys

Teratoma - physical exam

Palpable mass either externally or internally, signs of spinal cord compression: Sacrococcygeal tumor

Vaginoscopy reveals a polyploid lesion arising from the vaginal wall: Examination under anesthesia usually necessary

Palpable abdominal mass, peritoneal symptoms: Ovarian mass may be large

Palpable mass in scrotum: Testicular origin

Decreased breath sounds, consolidation, wheezing, superior vena cava syndrome: Mediastinal mass may be an emergency.

Teratoma - tests

Teratoma - lab

Serum α-fetoprotein (AFP) and β-human chorionic gonadotropin (β-HCG): Pure teratomas are not associated with elevated tumor markers. Elevation of either of these markers indicates the presence of more malignant germ cell elements and requires review of the histologic material.

CBC and chemistry profile, with electrolytes, BUN, creatinine, liver function tests, uric acid, and lactate dehydrogenase: Workup to rule out other malignancies or associated organ dysfunction

Teratoma - imaging

Plain radiograph: May reveal mature calcified tissues, such as bone or teeth, within tumor

Chest radiograph: Shows mediastinal mass

CT scan: Necessary to evaluate the primary site and regional disease

Prenatal MRI for fetal sacrococcygeal teratoma diagnosed by ultrasound: Allows more accurate prenatal counseling and improved preoperative planning

Chest CT and bone scan: If malignancy is suspected or proven, these are indicated for evaluation of metastasis.

Ultrasound, if CT is not readily available:

o May be helpful, but will rarely suffice as the sole imaging study of the primary site

o May be 1st evidence of anterior sacrococcygeal mass or to differentiate testicular mass from hydrocele

Teratoma - differencial diagnosis

Sacrococcygeal: Pilonidal cyst, meningocele, lipomeningocele, hemangioma, abscess, bone tumor, epidermal cyst, chondroma, lymphoma, ependymoma, neuroblastoma, glioma

Abdominal: Wilms tumor, neuroblastoma, lymphoma, rhabdomyosarcoma, hepatoblastoma, retained twin fetus

Vaginal: Rhabdomyosarcoma (sarcoma botryoides), clear cell carcinoma

Ovarian: Cyst, appendicitis, pregnancy, pelvic infection, hematocolpos, sarcoma, lymphoma, other ovarian tumors

Testicular: Epididymitis, testicular torsion, infarct, orchitis, hernia, hydrocele, hematocele, rhabdomyosarcoma, lymphoma, leukemia, other testicular tumors

Mediastinal: Hodgkin and non-Hodgkin lymphoma, leukemia, thymoma

Teratoma - TREATMENT

Teratoma - surgery

Every effort should be made to preserve fertility in gonadal teratomas. An experienced pediatric–gynecology oncologic surgeon is critical.

Sacrococcygeal teratomas should undergo complete resection to include

the coccyx, and patients followed closely postoperatively with tumor markers.

Mature teratoma: Full surgical excision, irrespective of site, is curative in prepubescent patients. One exception is in postpubescent testicular teratoma, where aggressive surgical resection, lymph node dissection, and postsurgical chemotherapy are recommended.

Immature teratoma:

o Complete surgical resection is therapy of choice.

o In cases of elevated AFP and incomplete surgical resection; chemotherapy should be offered given risk of microscopic foci of endodermal sinus tumor.

Teratoma with malignant components:

o Surgery plus chemotherapy with etoposide, cisplatin or carboplatin, and bleomycin

o Patients with residual disease should have additional surgery and additional chemotherapy if total resection is not possible.

o High-dose chemotherapy with autologous stem cell support and radiation are reserved for salvage therapy in recurrent disease.

Teratoma - FOLLOW UP

Serial physical exams and imaging studies of primary site

Tumor markers (AFP or β-HCG) if elevated at diagnosis

If chemotherapy or radiation therapy used, need to monitor for secondary malignancies, long term. Short term,

need to monitor blood counts, chemistries, renal function, and audiology

Teratoma - CODES

Teratoma - icd9

186.9 Benign

653.7 Sacral

Teratoma - FAQ

Q: What is the chance of cure for malignant teratomas?

A: With current chemotherapy as outlined above, diseasefree survival is 85%.

Q: Can a benign tumor recur? If so, can it then be malignant?

A: Yes. If there is residual tissue left behind, the tumor can recur. If there were unrecognized areas of malignancy, the recurrence can be a malignant teratoma. The greatest risk for the latter is with the immature teratomas.

Sacrococcygeal Teratoma Posted by Surgeon

Sacrococcygeal teratoma is the tumor arising in sacrococcygeal region & it is the commonest tumor found in newborns. It is also seen in infants, children & very rarely in adults. The SCT is more common in girls than boys with ratio of 3:1. The routine use of prenatal ultrasound has made the diagnosis early during fetal life.

Symptoms:1. Sacral mass2. Mass in the abdomen & perineum3. Distension of abdomen

4. Displacement of anus due to sacral mass5. Constipation6. Sacral sinus.

Classification: Altaman's classificationType 1- Entirely outsideType 2- Mostly outsideType 3-Mostly insideType 4- Entirely inside

Diagnosis:1. Prenatal Ultrasound- Solid/ cystic mass occupying abdomen as well as perineum2. CT Scan abdomino-pelvic region/ MRI abdomino-pelvic region3. Tumor markers- AFP or Alfafetoproteins

Treatment:1. Surgical excision in benign or mature teratoma2. Associated with chemotherapy in malignant or immature teratoma

Chemotherapy:Bleomycin, Etoposide & Cisplatin (BEP) protocol is the commonest first line protocol used.

Prognosis- Good if complete surgical excision is done along with removal of coccyx.