ULTRASOUND IN SACROCOCCYGEAL TERATOMA 

 

  • Sacrococcygeal teratomas (SCT) are commonly very large ( average 8-10 cm ), well encapsulated and grossly lobulated.
  • Mass in fetal pelvis containing two separate but adjacent components:
    • Solid echogenic component.
    • Cystic component (1). The presence of functioning choroid plexus, is thought to be responsible for the cystic component.
    • Echogenic foci with acoustic shadowing are thought to represent calcific areas of either bone or occasionally dystrophic calcifications.
  • 10-20 % are purely cystic (2).
  • Depending on the type it may have internal or external components or both.
  • Found posteriorly between the bladder and sacrum.
  • There may be vertebral body anomalies (3).
  • Amniotic fluid usually normal.
  • ± Polyhydramnios (70%).
  • ± Genito-urinary tract abnormalities (4).
  • Only 2 per cent of the SCT grow into the spinal canal
  • Non-immune hyrops may be seen in up to 25% of cases and is a poor prognostic indicator (thought to be due to large amounts of arterio-venous shunting by these large tumors).
  • Color doppler may demonstrate arteriovenous shunting in the larger solid lesions. This may result in high output cardiac failure in the fetus (polyhydramnios and fetal hydrops). Mortality rate is 28%-46% in the presence of fetal hydrops.
  • Color doppler also results in better delineation of individual vessels over longer lengths with better arborization (5).  Color and power doppler is done to visualize the degree of vascularity of the solid component.
  • They may show rapid growth in utero and result in intrauterine fetal demise, prematurity or exsanguinating tumor hemorrhage at delivery.

 

Type I Sacrococygeal Teratoma

 

 

Solid component

Color doppler – avascular when no shunting present

Color Doppler – vascular shunting through solid components of the tumor

 

 

 

Cystic component

 
Type 3 Sacrococcygeal teratoma

 

 

 

 

Large external component

Type 4 Sacrococcygeal Teratoma

MRI Scan of Type I Sacrococcygeal  Teratoma (30 wks GA)

 

 

 

 

Video clip of Sacrococcygeal Teratoma

 

 

 

 

REFERENCES
  1. Shipp TD, Shamberger RC, Benacerraf BR. Prenatal diagnosis of a grade IV sacrococcygeal teratoma. J Ultrasound Med 1996;15:175-177.
  2. Abrahim-Zadeh R, Coleman BG. The role of color doppler ultrasonography in obstetrics. Semin Roentgenol 1998;33(4):351-359.
  3. Evans MJ, Danielian PJ, Gray ES. Sacrococcygeal teratoma: a case of mistaken identity. Pediatr Radiol 1994;24:52-53.
  4. Bale PM. Sacrococcygeal developmental abnormalities and tumors in children. Perspect in Pediatr Pathol 1984;1:9-56.
  5. Fox DB, Bruner JP, Fleischer AC. Amplitude based color doppler sonography of fetus with sacrococcygeal teratoma. J Ultrasound Med 1996;15:785-787.
  6. el-Quarmalawi MA, Saddik M, el Abdel Hadi F, et al. Diagnosis and management of fetal sacrococcygeal teratoma. Int J Gynecol Obstet 1990;31: 275-281.
  7. Sheth S, Nussbau AR, Sanders R, et al. Prenatal diagnosis of sacrococcygeal teratoma: sonographic-pathologic correlation. Radiology 1988;169:131-136.
  8. Ein SH, Adeyemi D, Mancer K. Benign sacrococcygeal teratomas in infants and children: a 25 year review. Ann Surg 1979;191:382-384.
  9. Altman RP, Randolph JG, Lilly JR.  Sacrococcygeal teratoma: American Academy of Pediatrics Surgical Section survey - 1973. J Ped Surg 1974; 9:389-398.
  10. Holzgreve W, Flake AW, Langer JC.  The fetus with sacrococcygeal teratoma. In Harrison M, Golbus M, Filly RA (eds). The unborn patient. Philadelphia: WB Saunders 1991, p460-9.
  11. Kuhlmann RS, Warsof SL, Levy DL, et al. Fetal sacrococcygeal teratoma. Fetal Therapy 1987; 2:95-100.
  12. Lees RF, Williamson BR, Brenbridge AN, et al. Sonography of benign sacral teratoma in utero. Radiology 1980;134:717-718.
  13. Sherowsky RC, Williams CH, Nichols VB, et al. Prenatal ultrasonographic diagnosis of a sacrococcygeal teratoma in twin pregnancy. J Ultrasound Med 1985; 4:159-161.
  14. Holzgreve W, Miny P, Anderson R, et al. Experience with 8 cases of prenatally diagnosed sacrococcygeal teratomas. Fetal Therapy 1987;2: 88-94.
  15. Flake AW, Harrison MR, Adzick NS ,et al. Fetal sacrococcygeal teratoma. J  Ped Surg 1986;21: 563-566.
  16. Langer JC, Harrison MR, Schmidt KG, et al. Fetal hydrops and death from sacrococcygeal teratoma: Ratonale for fetal surgery. Am J Obstet Gynecol 1989; 160:1145-1149.
  17. Hogge WA, Thiagarajah S, Barber VG, et al. Cystic sacrococcygeal teratomas:ultrasound diagnosis and perinatal management. J Ultrasound Med 1987; 6:707-710.