Fetal tumors Flashcards
What is a sacrococcygeal teratoma?
A neoplasm composed of tissues from either all three germ layers or multiple foreign tissues lacking an organ specificity arising in the sacrococcygeal region. Though to arise from a totipotent somatic cell originating in Hensen’s node (enlarged group of cells located in the anterior portion of the primitive streak in a developing gastrula)
Type I SCT
Completely external, no presacral component
Type II SCT
External component and internal pelvic component
Type III SCT
External component and internal pelvic component extending into abdomen
Type IV SCT
Completely internal and no external component
Incidence & epidemiology of SCT
One of the most common tumors in newbornsStill rare - 1 in 30,000 livebirths
SCT - more common in males or females?
Females 4x as likely to be affected as males
Malignant transformation of SCT - more common in males or females?
Males
Characteristics of SCT
Most are solid or mixed solid & cystic. Purely cystic has also been described. Calcifications can be seen microscopically, but usu not visible by prenatal USMost are extremely vascular
Other US findings associated with SCT
Polyhydramnios - renal hyperfiltration due to high-output stateHepatomegalyPlacentomegalyNonimmune hydropsHigh-output failure may be due to tumor hemorrhage, severe anemia, or AV shunting within the tumor
Anomalies associated with SCT
Incidence of coexisting anomalies is 11-38%CNSGIGUMusculoskeletal
Is karyotype recommended for SCT?
Not unless there are multiple anomalies, AMA, or fetal surgery contemplated
Use of MRI for SCT?
May be useful in defining the pelvic component of SCT and impact on other pelvic structures, exclude MMC, can aid in operative planning
DDx of SCT
Lumbosacral MMCNeuroblastomaGliomaHemangiomaNeurofibromaCordomaLeiomyomaLipomaMelanoma50 other tumors in the sacrococcygeal region
Mortality rate for fetal vs neonatally dx’d SCT
50% fetal, 5% neonatal
Incidence of malignant elements in fetal SCT
Ranges from 7-30%, more common in males and in solid tumors
Antenatal history of SCT
27 cases - 5 TOP, 15 IUFD or NND (hydrops or poly in 7/7 IUFDs)15 cases - 6 survivorsHydrops in SCT is usually, but not always, fatal
Blood supply to SCTs
Classically thought to be middle sacral arteryMay “parasitize” blood supply from internal and external iliacs, resulting in vascular steal from UA placental blood flow, may lead to AEDF or REDF
Primary cause of death in fetal vs neonatal SCT
Fetal - tumor hemorrhage at deliveryNeonatal - prematurity, malignant invasion
Management of pregnancy in SCT
Weekly US for AFI, tumor growth, fetal well-being, hydropsSerial Doppler echo for signs of high-output state (incr diameter of IVC (> 1cm), incr descending aortic flow velocity (>120 cm/s), incr CO (>500 mL/kg/min)Delivery once FLM after 36wSVD if small tumor
Complications of vaginal delivery in SCT
Fetal death after rupture, avulsion, or asphyxiaCD recommended to avoid trauma-induced hemorrhage or dystocia, especially in large (>5-10 cm) tumors. A large tumor may warrant a classical uterine incision, esp in a preterm infant
When should fetal intervention be considered for SCT?
In utero resection for large SCT, early signs of hydrops or placentomegaly
Treatment of the newborn with SCT
Neonatologist to provide resp supportCareful handling to prevent exsanguinating hemorrhageExcellent venous access, UA and UV cathetersPressors to support hyperdynamic stateTransfusion may be necessaryUrgent resection if hyperdynamic stateSerum AFPs as a marker for recurrence post resection
Long-term outcome in SCT
Limited dataIf benign, usually no serious bowel or bladder dysfunction after surgery, most neonates do well following resectionNeurogenic bladder not uncommon if large pelvic componentSubtle gait abnormalities
Recurrence risk in SCT
Some cases appear famillial, with AD inheritanceFamilial SCTs are more often Type IV and can be missed, also assoc with anorectal malformations (anal stenosis)Rare cases of chrom abnl including distal 10q trisomy syndrome, mosaic trisomy of 1q, and de novo translocation btw 2 and 7
What is Currarino’s triad?
Familial cases of SCT can present as part of this triad - presacral tumor, anorectal malformations, and sacral anomaly
