Sacrococcygeal teratomas are benign or malignant tumors composed of germ cells that most commonly occur in the sacrococcygeal region. They can be classified as mature teratomas containing fully differentiated tissues, immature teratomas with incompletely differentiated tissues, or malignant teratomas containing malignant elements. Diagnosis involves prenatal ultrasound, postnatal radiological imaging and tumor marker testing. Treatment is complete surgical excision of the tumor and coccyx to prevent recurrence, with chemotherapy potentially used for malignant components. Long term follow up monitors for recurrence or complications.
3. Introduction
• Germ cell tumours are benign or malignant tumours that are
comprised mostly of germ cells.
• Germ cells are the cells that develop in the embryo and become the
cells that make up the reproductive system in either sex.
4. Cont …
• The term germ cell tumour (GCT) encomprises a larger group
including the mature and the immature teratomas, germinomas,
embryonal carcinomas and choriocarcinomas.
• The germ cell tumours may arise in the gonads or in extragonadal
sites, including the brain, face, neck, mediastinum, retroperitoneum,
and sacrococcygeal region.
6. TERATOMAS
• Teratoma, from the Greek teratos (‘of the monster’) and onkoma
(‘swelling’)
• Arise due to abnormal differentiation of the fetal germ cells that
arises from the fetal yolk sac
• The tumour is composed of all three germ cells layers ( i.e ectoderm,
mesoderm and endoderm) and has thus been reported to contain
hair, limbs, thyroid tissues etc.
8. Cont…
• The tumor sometimes consists of more organized tissue, such as small
bowel, limbs, and even a beating heart : These have been called
FETIFORM
• When the mass includes vertebrae or notochord and a high degree of
structural organization, the term FETUS IN FETU is used
9. Etiology
• The etiology of SCT is unknown, however different theories have been
put forward to explain the pattern of its occurrence :
Theories
I. Cell migration theory
II. Primitive streak/Node theory
III. Incomplete twinning theory
10. I. Cell migration theory
• Teratomas are thought by some to arise from totipotent primordial
germ cells.
• These cells develop among the endodermal cells of the yolk sac near
the origin of the allantois and migrate to the gonadal ridges during
weeks 4 and 5 of gestation
• Some cells may miss their target destination and give rise to a
teratoma anywhere from the brain to the coccygeal area, usually in
the midline.
12. II. Primitive streak/Node theory
• During week 3 of development, midline cells at the caudal end of the
embryo divide rapidly and, in a process called gastrulation giving rise
to all three cell layers of the embryo
• By the end of week 3, the primitive streak shortens and disappears.
• This theory explains the more common occurrence of teratomas in
the sacrococcygeal region.
14. III. Incomplete twining
• Less popularized theory
• Although not confirmed in all series, this finding, combined with
reports of simultaneous twin pregnancy or sequential familial
occurrences of fetus-infetu and teratoma, supports the theory that
teratomas may be just one end of the spectrum of conjoined twinning
15. Epidemiology
• Sacrococcygeal teratomas are the most common extra-gonadal tumor
in neonates, accounting for up to 70% of all teratomas in childhood
• Incidence is 1/35000 – 40000 live births
• A 3 to 4:1 female to male ratio is generally reported
• SCTs with malignant elements generally are not seen in infants
• Incidence of malignant element tend to increase with age as 90% of
lesions are benign at birth
18. Pathology : Histology
• Comprised of cells that represents all three cell germ layers
• They have solid, cystic or mixed components
• Unlike teratomas in other locations, SCTs often do not have capsule or
pseudo-capsulated which accounts for the difficultness in achieving
tumor free margin
• Sampling of entire tumour is essential to ensure no immature neural
elements of occult foci of malignancy are present
20. Other pathological classifications
1. Matured teratoma
Consists of fully differentiated tissues from various somatic cells.Can include
fully functional glandular structures such as pancreatic langer- hans . Can
have fully developed hairs, bones and teeth.
Rare Mallignant Transformation (1-3% Reported)
2. Immature teratoma
With small fraction of cells with incomplete differentiated tissue structures
Has prominent solid components with cystic elements and it is usually filled
with lipid constituents therefore demonstrate fat density on CT or MRI
Mallignant Transformation Is Common
21. Cont…
3.Mallignant Teratoma
• Contain malignant element ( Between 11 – 35% of all SCTs are
malignant) and many of these will have elevated tumor markers
• The most common malignant element is the YOLK sac element which
produces AFP
• Microfoci of malignant element can be missed on pathological
sectioning, therefore screening with AFP and B-hcg has become part
of initial evaluation to patients with SCTs
26. Associated anomalies and presentations
• Teratomas are usually isolated lesions.
• A well-recognized association is the Currarino triad of anorectal
malformation, sacral anomaly, and a presacral mass
• The female preponderance for patients with this triad is only 1.5:1,
which is less than the 3:1 ratio noted in isolated SCTs.
• A familial predisposition is noted in 57% of cases and has an
autosomal dominant inheritance pattern.
• By far the most common is anal or anorectal stenosis.
27. • Malignant transformation of a presacral teratoma in the context of
the Currarino triad have appeared, and the risk of malignant
transformation has been estimated at 1%
• This malignant transformation can occur well into adulthood ( one
case reported at 69 yrs and the youngest one at 13yrs)
• Hirschsprung disease has been incorrectly diagnosed in some cases
because constipation is a frequent presenting symptom of the
Currarino triad
28. Other anomalies
Urogenital anomalies, such as:
• hypospadias,
• Vesicoureteral reflux,
• vaginal or uterine duplications
Other syndrome has been associated with non sacrococygeal lesions
like klinefelter syndrome, trisomy 13,trisomy 21,congenital heart
defects and Beckwith widemann syndrome
29. Common presentations
• Most sacrococcygeal teratomas are visible externally and are
therefore diagnosed clinically at birth.
• It might be asymptomatic in infancy or present with obstructive
symptoms unto the rectum or urinary bladder
• A small number of children will present with weakness, pain or
paralysis
• In utero : Featal distress, congestive heart failure leading to hydrops
fetalis, intratumoral hemorrhage and even pre term delivery.
30. Ddx
The differential diagnosis of a sacrococcygeal teratoma is mainly
meningocele or myelomeningocele.
• However, myelomeningocele can be distinguished on the basis of its
more completely cystic nature and its less abundant internal
component.
• In addition, pressure on a myelomeningocele will often be noticeably
transmitted to the anterior fontanelle.
34. Pre natal diagnosis : USS
• The routine application of prenatal ultrasound has increased the
prenatal diagnosis of sacrococcygeal teratomas and allowed for
accurate identification of their site and details of any intrapelvic
extension or urinary tract obstruction.
• Repeated ultrasound assessment of tumor size also helps determine
the mode of delivery.
• Cesarean section delivery is advocated for tumors larger than 5 cm so
as to avoid dystocia, tumour rupture and more adversely death
35. Cont …
• Finally, ultrasound may be used to prognosticate lesions.
• Polyhydramnios(27 percent), placentomegaly, and hydrops fetalis are poor
prognostic indicators.
• Polyhydramnios is associated with premature labor.
• 20% of tumors diagnosed prenatally develop hydrops from high output
cardiac failure secondary to vascular steal of blood flow through
arteriovenous channels within the tumor, which is associated with a near-
100% mortality
36. Diagnosis & evaluation in the neonate and
children
• Consider gross clinical diagnosis: and hence most require evaluations
even after clinical dx
I. Radiological investigations
II. Laboratory investigatiions
40. 2. CT SCAN & MRI
• Detailed preoperative assessment of the lesion, any abdominal or
pelvic extension, and its relationship to the adjacent structures, is
made by computed tomography (CT) and/or magnetic resonance
imaging (MRI).
43. 3. XRAY
• Can be usefully to asses the presence of an associated anomalies
especially The curarino triad
• Can hence asses the presence of hemisacrum, bifid sacrum, no
sacrum and even the anal/rectal stenosis (with the aid of a contrast) .
46. Laboratory evaluation
• Most common produced tumour markers AFP and B-hcg should be
evaluated as the baseline diagnostic workup to look for malignant
components
• Also can be used to asses and monitor tumour relapse during post op
period
48. Prenatal management
• Following intrauterine diagnosis of the tumor, management is based
on fetal lung maturity and the presence or absence of placentomegaly
and hydrops fetalis (the latter conditions being associated with almost
100 percent mortality).
• Upon fetal lung maturity without placentomegaly and/or hydrops
fetalis, early elective delivery by Cesarean section is indicated.
49. Fetal intervention
• Fetal interventions like amniodrainage, cyst aspiration, relief of
bladder outflow obstruction can be performed in those cases were
hydrops and prematurity is present.
• Intrauterine endoscopic laser ablation ,radiofrequency ablation can
also be done
50. Consideration of open fetal surgery for debulking of SCTs is only
considered in very selective cases such as:
• Type 1 SCT
• GA of 20 – 30 weeks
• Absence of placentomegally
• An early hydrops
51. Postnatal
• The main stay of Rx is early and en-block excision of the lesion
provided that:
I. The risk of malignant change in benign lesions increases with
Age
Incompletely excised residual lesion
II. The tumour’s rich vascularity makes it vulnerable to spontenous
ulceration and hemorrhage if left unexcised
52. Preoperative preparation and
anesthesia
1. Appropriate imaging (ultrasonography/CT/MRI) to delineate the
anatomy and extent of the lesion, as the surgical approach will be
dictated by whether the lesion has intra-abdominal or intrapelvic
extension.
2. Serum assays of tumor markers (AFP/β-hCG) for postoperative
comparisons.
3. Adequate intravenous access and blood products should be secured
before starting the operation, especially with large tumors, where there
may be brisk intraoperative blood loss.
Other vascular access, including an arterial line for blood pressure
monitoring, and central venous line monitoring are beneficial.
53. Cont …
4. General anesthesia is mandatory : High-output cardiac failure
secondary to arteriovenous channels in the tumor may limit the use of
inhalation agents, which have known cardiodepressant effects.
5. Broad-spectrum antibiotics should be given as a prophylaxis
6. The stomach is emptied with a nasogastric tube and an indwelling
bladder catheter is inserted.
56. Stage 3:
• Removal of tumor and coccyx
en- bloc and ligation of sacral
vessels
• Failure to remove the coccyx is
associated with a 30–40 percent
incidence of recurrence, with
more than 50 percent of cases
becoming malignant.
57. Cont…
• This dissection can be facilitated
if necessary by placing a finger in
the rectum.
• Rarely, the tumor completely
surrounds the rectum, making
total excision very difficult.
• The excised tumor is sent for
histological examination to
identify the presence of any
malignant components as well
as to ensure tumor-free margins.
58. Stage 4: Pelvic floor reconstruction
• The pelvic floor is reconstructed
by suturing the superior and
posterior portions of the levator
muscles to the presacral fascia,
behind the rectum.
• This allows the anus to assume a
near-normal configuration and
therefore the best possibility of
achieving good fecal continence
59. Stage 5: Closure
• The gluteus maximus muscles
are apposed in the midline using
interrupted sutures.
• A drain may be left in place in
the perirectal space prior to this
closure, and brought out
through a separate stab incision.
60. Modifications for extensive or intra-abdominal
tumors
• In type III tumors where there
is significant intraabdominal
involvement, the pelvic
excision must be preceded by
a laparotomy.
• In these cases, the operation
commences with the patient
in a supine position, with a
rolled gauze pad under the
buttocks, thus raising the
pelvic floor.
• A lower midline or transverse
lower abdominal incision
approach is used, depending
on the extent of the intra-
abdominal component of the
tumor.
• The tumor is dissected free
from the lower abdominal and
pelvic viscera, and the sacral
vessels can be controlled
through this approach.
61. …
• The abdominal wall is then
closed, and the patient is turned
prone to complete the operation
as described above
62. Role of laparoscopy
• Laparoscopy can be used for the resection or mobilization of intra-
abdominal or pelvic portions of the SCT.
• This is combined with the external resection of the tumor and for
litigation of the sacral vessels.
63. Role of Chemotherapy ( neo and adjuvant)
• Malignant lesions respond poorly with surgery alone, with a 10
percent salvage rate.
• Adjuvant chemotherapy, particularly platinum-containing regimens,
e.g. cisplatin, bleomycin, vinblastine, and/or VP-16 (etoposide),
addressing the specific malignant element, has improved survival
with such lesions.
• This regimen may shrink the tumor, making it amenable to secondary
resection.
• Resected tumors should also be examined for malignant elements,
which may require subsequent chemotherapy.
65. Follow-up
It is important to monitor all patients with physical examination,
including
• Rectal examination
• Serum markers (AFP, B-hcg and CA 125)
• Note: AFP levels decreases and reaches adult levels @ 8 months
when ?
• Initial is day 5 to 7 post op (for tumour markers AFP – t1/2 =6 days))
then
• Every 2 or 3 months for At least 3 years ( both DRE and markers) ,
because most recurrences occur within 3 years of operation
66. Cont …
• In addition to tumor recurrence, long-term complications associated
with sacrococcygeal teratomas are common:
40% will encounter mild bowel dysfunction (incontinence or
constipation),
10% percent will have urinary incontinence or neuropathic bladders,
often associated with similar bowel symptoms.
• These patients required treatment and constant vigilance to prevent
further problems.
67. References
• Ashcraft 7th edition
• Operative Pediatric Surgery 7th Ed 1
• Coran Pediatric Surgery, 7th ed, 2012
• Operative Pediatric Surgery 2nd Ed
• Paediatric Surgery For Africa V-II
• Altman RP, Randolph JG, Lilly JR. Sacrococcygeal teratoma: American
Academy of Pediatrics Surgical Section Survey-1973. J Pediatr Surg.
1974;9:389–398.
• Derikx JP, De Backer A, van de Schoot L, et al. Factors associated with
recurrence and metastasis in sacrococcygeal teratoma. Br J Surg.
2006;93:1543–1548.
