**2.2 Classification**

Size of a SCT (average 8 cm diameter, range 1–30 cm) does not predict its biological behavior. Altman et al. defined the size of SCT as follows:

Small: as 2–5 cm diameter

Moderate: 5–10 cm

Large: >10 cm.

Antenatal diagnosis is important to avoid complications during delivery. Fetal US and MRI are the mainstay of antenatal diagnosis of SCT. MRI is more accurate in describing the intrapelvic and abdominal extent of the tumor and provides more information on compression of adjacent organs. Prenatal assessment of the fetus is critical for counseling the parents and planning surgical options. Because of acoustic shadowing by the fetal pelvic bones, US cannot always define the extent of SCT. Fetal MRI has been successfully performed to evaluate anatomy, content and extent of the tumor, but just a few small cases series have been published yet.

SCT arise from the base of the coccyx and may continuously grow in the posterior direction forming an external protrusion, or in the anterior direction, dissecting and distorting surrounding structures such as the rectum, vagina and bladder, but without invading them. Based on this morphologic characteristic, Altman et al.

**59**

*Prenatal Diagnosis and Management of Sacrococcygeal Teratomas*

have been defined The American Academy of Pediatrics Surgical Section (APPSS)

Type I: predominantly external with minimal presacral component—45.8% Type II: present externally, but with significant intrapelvic extension—34% Type III: apparent externally but predominantly a pelvic mass extending into the

Type IV: presacral mass with no external presentation—9.6%.

Grade 2—tumor contains moderate quantities of immature tissues

Grade 3—tumor contains large quantities of immature tissue with or without

The majority of SCT present between the 22nd and the 34th week of gestation. The diagnosis of SCT on routine US is associated with a greater than expected incidence of prenatal and perinatal complications. Close antenatal follow up is needed to optimize patient counselling and treatment in the presence of a completely solid tumor and the onset of polyhydramnios. A poor outcome is usually correlated with

Associated congenital malformations are observed in 12–15% of cases and occur more frequently with presacral tumors. The incidence of various congenital malformations associated with SCT ranges from 5 to 26%. Of these, anorectal and genital malformations are most commonly. A growing SCT during the first weeks of embryonic life will encroach between the layers of the cloacal membrane and prevent descent and fusion of the urorectal septum to the cloacal membrane, resulting in a high anorectal malformation with a rectourethral or rectovestibular fistula. The presence of SCT in the same period of time (47th weeks), when cloaca is subdivided by the urorectal septum to form the anorectal canal and the primitive urogenital sinus, could prevent fusion of the genital folds, resulting in a bifid scrotum or hypospadias. The most commonly observed anorectal defects are: imperforate anus, anorectal stenosis and common vertebral anomalies are: sacral hemivertebrae,

Other associated anomalies include spinal dysraphism, sacral agenesis, dislocation of the hips and meningocele. Rarely, gastrointestinal or cardiac defects are

Currarino triad represents association of anorectal malformation, sacral dysplasia and presacral mass. Delay in diagnosis of the presacral lesion is common because a rectal examination may not be possible in many cases with anorectal stenosis. Presenting symptoms in some of these unusual cases include perirectal abscess or

Grade 1—tumor contains rare foci of immature tissues

placentomegaly, cardiomegaly or non-immune hydrops fetalis.

*DOI: http://dx.doi.org/10.5772/intechopen.87987*

SCT are graded histologically as follows: Grade 0—tumor contains only mature tissue

classification [3–5]:

abdomen—8.6%

**2.3 Histology**

**3. Diagnosis**

malignant yolk sac elements.

**3.1 Intrauterine diagnosis**

**3.2 Associated anomalies**

absence of the sacrum and coccyx [6].

associated with SCT.

fistula in ano (**Figure 1**).

*Prenatal Diagnosis and Management of Sacrococcygeal Teratomas DOI: http://dx.doi.org/10.5772/intechopen.87987*

have been defined The American Academy of Pediatrics Surgical Section (APPSS) classification [3–5]:

Type I: predominantly external with minimal presacral component—45.8% Type II: present externally, but with significant intrapelvic extension—34% Type III: apparent externally but predominantly a pelvic mass extending into the abdomen—8.6%

Type IV: presacral mass with no external presentation—9.6%.
