Sacrococcygeal Teratoma -Paediatric Surgery Unit

SACROCOCCYGEAL TERATOMAPAEDIATRIC SURGERY UNIT

OUTLINE• CASE PRESENTATION• INTRODUCTION• RELEVANT ANATOMY• AETIOPATHOGENESIS• PATHOLOGY/ CLASSIFICATION• PATHOPHYSIOLOGY• CLINICAL FEATURES/ DIFFERENTIALS• INVESTIGATIONS• TREATMENT• COMPLICATIONS• LOCAL EXPERIENCE• CONCLUSION

CASE PRESENTATION

• A.G.• F/14MONTHS• RESIDED IN BENIN CITY• First seen by the unit at 2hrs of life with c/o

swelling at the lower back• Was delivered at 33+4wks gestation via ELCS to

a 30yr old P3 lady, due to reduced fetal movement

• Had earlier had a fetal USS diagnosis of sacrococcygeal mass at 32wks gestation

• At delivery, APGAR score was 61,85,1010 • Weight -4.4kg• MSS- Huge swelling in the sacrococcygeal

region, 20x15cm, surface lobulated and shining with prominent dilated vessels. Soft and cystic ,did not transilluminate and was non reduceable.

• CVS- HR-140bpm, -HS :S1,S2

• Other systems- normal• Ass- Preterm neonate with Huge

sacrococcygeal teratoma• Had a gross total excision of the tumour 4 days

later

• Findings- 1) Huge SCT weighing 2.3kg containing cystic and solid components 2)Displaced anal opening(to the left)

• Histology- An unencapsulated neoplastic lesion lined by skin and containing immature cartilage, unremarkable glands and mesenchyma

• Diagnosis- Features are in keeping with a BENIGN CYSTIC TERATOMA

• Post Op: managed in SCBU with antibiotics as a case of Preterm ? LBW

• Discharged on the 26th DPO• Had 3 SOP visits thereafter• 15th Month Post Op: Presented in CHER with

c/o Inability to pass stool x1/52, Inability to pass urine x1/7

• Examination- Abdomen- full, moved with resp, suprapubic fullness. L0 K0 S0

• Rectal- poor perianal hygiene, lax anosphincteric tone, non tender mass at the right rectal wall, examining finger could not get above it. Rectal mucosa mobile over it

• Impression- Bladder Outlet Obstruction 20 tumour recurrence ? mitotic

• Admitted and catheterised and commenced on antibiotics

• 2nd day on admission- developed haematuria• Was reviewed by the paediatric oncologist and

she was to commence cytotoxic chemotherapy

• A repeat biopsy was requested by the pathologist

• Child finally succumbed before another biopsy could be done.

CASE 2

• I. W.

• MALE / 9 MONTHS

• IRO, ONDO STATE

• CHRISTIAN

• URHOBO

• PRESENTED WITH – Abdominal swelling and difficulty with urination x 2/52 -INABILITY TO PASS URINE X1/7

• 2 WEEKS BEFORE PRESENTATION,• NOTICED REDUCTION IN URINE OUTPUT ASSOCIATED WITH

– ABDOMINAL SWELLING

– MARKED IN LOWER ABDOMEN

– PROGRESSIVELY INCREASING IN SIZE

– POSITIVE HISTORY OF WEIGHT LOSS AND CONSTIPATION -NO

HAEMATURIA

– NO COUGH, NOR DYSPNEA

• ON THE DAY OF PRESENTION, THERE WAS SUDDEN INABILITY TO PASS URINE ASSOCIATED WITH IRRITABILITY

• PRESENTED IN UBTH 5MTHS EARLIER WITH – 4 WEEKS HISTORY OF SWELLING NOTICED AT LEFT

BUTTOCK (FIRST NOTICED AT 2WKS OF LIFE)

– PROGRESSIVELY INCREASING IN SIZE AND LATER ULCERATED

– A DIAGNOSIS OF SACROCOCCYGEAL TERATOMA WAS MADE AND THE MASS WAS THEN EXCISED

– PRESENTED 4 MTHS LATER WITH THE ABOVE SYMPTOMS

EXAMINATION• GENERAL– HEALTHY LOOKING, PALE, ANICTERIC, AFEBRILE, NIL PEDAL

EDEMA

• ABDOMEN– DISTENDED, MORE IN THE SUPRAPUBIC REGION, MOVES

WITH RESPIRATION, UMBILICUS EVERTED,

– SUPRAPUBIC MASS- SOFT, SMOOTH, TENDER, COULD GET ABOVE IT BUT NOT BELOW, PERCUSSION NOTE WAS DULL OVER IT

– LIVER, SPLEEN, KIDNEYS NOT PALPABLY ENLARGED

– GLUTEAL REGION- WELL HEALED PREVIOUS INCISION SCAR WITH NODULES UNDERNEATH SCAR, FIRM AND ATTACHED TO SKIN

– LEFT GROIN- FIRM MASS 8X 9 cm OVER LEFT GROIN ATTACHED TO UNDERLYING STRUCTURES, NO DIFFERENTIAL WARMTH

– BOWEL SOUNDS- NORMOACTIVE

– RECTAL- PERIANAL EXCORIATION, GOOD ANAL SPHICTERIC TONE, MASS FELT ANTERIOR-MEDIALLY, FIRM, SMOOTH, LOBULATED, ALMOST OCCLUDING RECTUM. GLOVED FINGER STAINED WITH ALTERED BLOOD AND STOOL

• OTHER SYSTEMS- N. A. D

• ASSESSMENT– RECURRENT SACROCOCCYGEAL TERATOMA WITH FEATURES

OF BLADDER OUTLET OBSTRUCTION (B. O.O)

– WAS CATHERISED IMMEDIATELY AND 400MLS OF URINE DRAINED

• ULTRA SOUND SCAN– FEATURES OF B. O. O WITH CYSTITIS AND BILATERAL

HYDONEPHROSIS

• HISTOLOGY OF PREVIOUSLY EXCISED MASS– SACROCOCCYGEAL MASS, FEATURES CONSISTENT WITH

POORLY DIFFERNTIATED CARCINOMA

• COMMENCED 1ST COURSE OF CHEMOTHERAPY– VINCRISTINE– ADRIAMYCIN– CYCLOPHOSPHAMIDE

• 2 DAYS LATER, HE BECAME DYSPNOEIC• CHEST X-RAY –MULTIPLE INFILTRATES IN THE

LUNG FIELDS• HE FINALLY SUCCUMBED 5TH DAY POST

CHEMOTHERAPY

INTRODUCTION

• Teratoma: from the Greek teratos which means "monster

• Sacrococcygeal teratoma (SCT) is the most common tumor of the newborn with an incidence of 1 in 35,000 to 40,000 live births

• Neoplasms that contain cellular or tissue derivatives of more than one of the primary germ cell layers of the embryo that are foreign to the anatomic region in which they arise

• In childhood, they normally occur as extragonadal masses located along the midline axis: about 40-50% occur in the sacroccocygeal region.

• Gonadal teratomas occur more frequently after puberty

• About 67% of sacroccocygeal teratomas are diagnosed by the age of 1 year.

• Occur at a rate of 1/25,000 to 1/40,000 live births.

• Females are affected over 75% of the time

ANATOMY

• THE SACRUM AND THE COCCYX ARE PART OF THE VERTEBRAL COLUMN IN THE PELVIC REGION

• FORM THE POSTERIOR PELVIC WALL• SACRUM CONSISTS OF FIVE RUDIMENTARY

VERTEBRAE FUSED TO FORM A SINGLE WEDGE SHAPED BONE

• ARTICULATES SUPERIORLY WITH L5 • INFERIORLY WITH COCCYX

EMBRYOLOGY

• Sacrococcygeal teratomas originate from Hensen's node (primitive knot), which is an area of the primitive streak.

• Hensen's node is an aggregation of totipotential cells that are the primary organizers of embryonic development.

• The primitive streak diminishes in size and becomes an insignificant structure in the sacrococcygeal region of the embryo, eventually disappearing.

• The primitive streak remnant may persist and give rise to a sacrococcygeal teratoma.

• These pleuripotential cells escape from the control of embryonic inducers and organizers

• Differentiate into tissues not usually found in the sacrococcygeal region

• The teratomas form and grow during intrauterine life

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

HYPOTHESES

• The prevailing hypothesis is that extragonadal GCTs arise from aberrant migration

• or the deposition of germ cells along the path of migration into areas that are not within the normal pathway (e.g. sacrococcygeal regions)

• or may remain outside the coalescence of gonadal tissue.

.

PATHOLOGY:HISTOLOGIC TYPES

• Mature teratomas• Benign-Most common type-Usually cystic

• Yolk sac (Endodermal sinus) tumours• Malignant-Composed of immature/embryonic elements-Usually solid-Aggressive clinical course

HISTOLOGIC GRADING

• Grade 0: tumour contains only mature tissue

• Grade 1: rare foci of immature tissue

• Grade 2: moderate quantity of immature tissue

• Grade 3: large quantity of immature tissue, with or without malignant yolk sac (endodermal sinus) elements

• Note: grading does not seem to correlate with prognosis

PATHOLOGY:ANATOMIC CLASSIFICATION

• The American Academy of Pediatrics Surgical Section (AAPSS ) classification system groups these tumors according to the relative amount pelvic or external tumor present.

• The importance of this classification relates to the ease of detection and resection and, consequently, survival.

Type 1

Tumors (47 % )are completely external :

Easily identified on prenatal ultrasound examination or at birth, leading to early referral and resection with less morbidity.

Type II

( 35 % ) has intrapelvic extension of SCT.

Type III

( 8 % ) has intra-abdominal extension

Type IV

( 9 % )tumors are completely internal Usually recognized late, after they have undergone malignant transformation and become symptomatic. Any type of SCT may have an intraspinal component

• the incidence of malignant components

correlates not only with anatomic type (8% in type I versus 38% in type IV)

• But also with age at diagnosis and gender; • however, the size of the tumor is unrelated• Also the more solid the tumour, the greater

the internal component,

• . Malignant change appears to be more frequent in males

• Particularly those with solid versus complex or cystic

• Hence:

• *SCT at age <2/12; 10% are malignant.

•

• *By age 1yr 37% ”

•

• *By age 2yrs 50% ”

PATHO-PHYSIOLOGY

• Tumors can grow at an unpredictable rate to tremendous dimensions

• May extend retroperitoneally, displacing pelvic or abdominal structures.

• . It is thought that a hyperdynamic state is induced by low resistance vessels in the teratoma.

• Large tumor "steals" blood from fetal circulation, causing the heart to work extra hard –vascular steal

• Making cardiac failure possible. • Cardiac failure is manifest as "hydrops," an

accumulation of fluid in the body of the fetus.• Also causes polyhydramious- preterm labor

• The association of fetal hydrops and Sacrococcygeal Teratoma is usually fatal, and always fatal prior to 30 weeks gestation.

• For the mother, there is the risk of “maternal mirror syndrome” in which the mom’s condition parallels that of the sick fetus

• Fetal anemia or fetal exsanguinations caused by spontaneous bleeding of the tumor or tumor rupture during delivery

• Neonatal death may occur due to obstetric complications from tumor rupture, preterm labor, or dystocia

CLINICAL PRESENTATION

• They present clinically as a large exophytic midaxial or gluteal mass located posterior to the sacrum.

• Sacrococcygeum is the most common location for non gonadal germ cell tumours 32-66%. It is the most common tumour in the newborn period 1 in 35,000 births.

• Protrudes b/w the coccyx & the rectum, nearly always arising from the tip of the coccyx

• Benign teratomas usually produce no functional impairment

• Presence of bladder or bowel dysfunction suggest malignancy.

Maternal Presentations

• History- Large for date abdomen, Swollen legs, Inability to pass urine, constipation, Lower limb weakness

• Examination- Pedal edema, Urinary retention, paraparesis

• During ante-natal ultra-sonography, which detects about 25% of cases of SCT

• watch out for:-• Polyhydramnios• Placentomegaly• Cardiomegaly• Fetal hypertension• Hydrops fetalis (i.e. CCF), &

•Maternal mirror syndrome, may be seen:»Hypertension»Oedema»Proteinuria»(i.e. pre-eclampsia)

Fetal Presentations

• High output heart failure• Birth dystocia• AAP class ii-iv tumours present with

constipation, urinary retention, decreased appetite, failure to thrive.

ASSOCIATED ANOMALIES

• Present in 20% of cases, & include:-• Anorectal malformations ; imperforate

anus • Genital malformations – bifid scrotum,

hypospadias, duplication of uterus/vagina• Others:

• Spinal bifida• Sacral agenesis/defects• Dislocation of hips, &

•Meningocele•Meningomyelocele• Abnormalities of the kidneys, CNS, heart,

alimentary tract

• Note the Currarino triad of• Anorectal stenosis• Sacral dysplasia, &• Presacral SCT.

Differential Diagnosis

• Sacral Meningoceles• Sacral Meningomyeloceles• Sacral Lipomeningoceles• Haemangiomas• Neuroblastomas• Rectal duplication cysts.

Epidermal cyst• Post anal dermoid cyst• Sacral chordomas• Sarcomas• Leiomas• Lipoma• Peri rectal abscess• Pilonidal cyst

INVESTIGATIONS

• X-ray of spine, abdomen, chest, pelvis• USS• CT/MRI• IVU• Myelogram• B-HCG• Alpha fetoprotein• ECHO/DOPPLER/ANGIOGRAPHY

TREATMENT

• Mainly surgical (complete resection of the tumour)

• Adjuvant therapy with cytotoxic chemotherapy is necessary if tumour is malignant

• Surgical mgt can be embacked upon postnatally as an emergency or elective; or prenatally

Pre-Op work Up

• Computerised Tomography• Magnetic Resonant Imaging• Chest X-ray• Angiography• ECG; ECHOCARDIOGRAPHY; ABDOMINAL USS• Alpha-fetoprotein• E/U/Cr• FBC• Coagulation Profile

Operative Goals

• Complete and Prompt Tumour Excision• Resection of the coccyx to prevent tumour

recurrence• Reconstruction of the muscles of anorectal

continence• Reconstruction to achieve a normal perineal

and gluteal appearance

Operative Approach

• Determined by anatomical location• Types iii &iv- Initially through the abdomen

(abdominosacral resection) +/- temporary colostomy

• Types i & ii- Posterior Sacral Approach

Operation (Posterior Sacral Approach)

• Patient is catherterised• Position- prone jack knife• Skin prep & Sterile drapping• Inverted V (Chevron) incision• Delineate the rectum with Heggar’sdilator• Raise skin flap off tumour• Identify and preserve retrorectal muscles

• Mobilise mass close to the capsule• Secure haemostasis• Divide coccyx from sacrum and excise in continuity with

tumour• Dissect tumour away from rectal wall• Reconstruct anorectal muscles• Place suction drains below subcut flaps• Close wound in layers with interrupted absorbable

sutures• Nurse patient prone

Fetal Teratoma

Adjuvant Therapy

• Detection of malignant elements warrant adjuvant multi-agent chemotherapy

• Most active agents- cisplatin, Etoposide and bleomycin

• Indications: -locally advanced tumour -Metastatic -unresectable tumour

• Radiotherapy- may have a role

Complications (Prenatal)

• Polyhydramnous• Placentomegaly• Heart failure (Hydrop fetalis)• Maternal “mirror” syndrome• Fetal Anaemia or Exsanguination• Dystocia

Postnatal

• Rupture/ haemorrhage• Ulceration• Heart failure• Coagulopathy (DIC)• Malignant transformation

Post Operative

• Intra Op Haemorrhage• Urinary retention• Fecal incontinence• Surgical site infection/ wound breakdown• Lower limb weakness

Prognosis

• Long term survival of newborns with SCT is generally excellent (92-95%)

• Surgical mortalities are usually related to coincidental birth anomalies or to haemorrhage during surgery

• Generally: Benign- Disease free survival is > 90% Malignant- Significant mortality

Prognostic Factors

• AGE: Fetal- Diagnosis made >30wks have better prognosis

Postnatal- <2 mths only 7-10% are malignant; 1yr, 30% are

malignant; 2yrs, 50% are malignant

• Nature of tumour- Cystic tumours are generally mature and carry better prognosis

Local Experience

• Between 2005 and 2010• Total- 6 cases• Sex Ratio: Female- 4; Male-2 (2:1)• Histology: 4-Benign; 2- Malignant• Malignant: 1 died; 1- Lost to follow-up• Benign: 1 died

Conclusion

• SCTs are treatable infantile tumours with excellent outcome

• These outcome is dependent on the above prognostic factor and prompt and aggressive intervention after diagnosis

• The need for follow up for at least 3yrs is mandatory due to high recurrence rate even in benign tumours

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