Pediatric Ovarian Teratoma

Mature Ovarian Teratoma

  • Etiology: Composed of 3 germ layers – ectoderm and mesoderm and endoderm so contains sebum and hair and fat and calcification and bone and teeth and serous fluid
  • Imaging:
    — Visualization of fat, calcium, and soft tissue in cystic pelvic mass is diagnostic of ovarian teratoma
    — Cystic, majority are unilocular, can have papillary projections
    — Can be large in size with average size 6.5 centimeters plus or minus 3.5 centimeters
    — 10% bilateral
  • Imaging US: Variable sonographic appearance
  • Note: Imaging cannot distinguish mature teratoma from immature teratoma
  • DDX: Immature ovarian teratoma, bowel gas, hemorrhagic cyst, endometrioma, perforated appendicitis with appendicolith
  • Complications: Ovarian torsion, infection, rupture, malignant transformation, auto-immune hemolytic anemia, anti-NMDA receptor encephalitis
  • Treatment: Surgical
  • Clinical:
    — Presentation is 60% asymptomatic, 23% abdominal pain, 3.5% ovarian torsion
    — Most common ovarian neoplasm in children
    — 90% of all benign ovarian neoplasms

Immature Ovarian Teratoma

  • Etiology: Composed of 3 germ layers – ectoderm and mesoderm and endoderm so embryonic tissue includes immature neural elements and 29-66% with yolk sac elements
  • Imaging:
    — Visualization of fat, calcium, and soft tissue in cystic pelvic mass is diagnostic of ovarian teratoma
    — More solid than mature teratoma, greater than 10 centimeters in size, irregular walls
    — Ascites
  • Note: Imaging cannot distinguish mature teratoma from immature teratoma
  • DDX: Mature teratoma, bowel gas, hemorrhagic cyst, endometrioma, perforated appendicitis with appendicolith
  • Complications: Ovarian torsion
  • Treatment: Surgical
  • Clinical:
    — Most common malignant germ cell tumor – 36% of malignant germ cell tumor
    — Mean age of 20 years and median age of 19 years

Radiology Cases of Ovarian Teratoma

AXR of ovarian teratoma
AXR AP shows an oval calcification in the right pelvis in the region of the right adnexa.

Radiology Cases of Mature Ovarian Teratoma

US and CT of ovarian teratoma in NMDA encephalitis
Sagittal US of the pelvis (upper left) shows the right ovary to be enlarged and to contain an echogenic lesion within it superiorly. Axial (upper right) and coronal (lower left) and sagittal (lower right) CT with contrast of the abdomen shows an enlarged right ovary in the midline of the pelvis anterior to the rectum which has multiple low density lesions within it.

Radiology Cases of Mature Ovarian Teratoma Causing Ovarian Torsion

CT of ovarian teratoma causing ovarian torsion.
Axial (above left), sagittal (above right) and coronal (below) CT without contrast of the abdomen show a large thick walled, fluid-filled, unilocular mass just above and to the right of the bladder which contains focal areas of fat density material and calcific density material. There is a small amount of ascites.
MRI of pediatric ovarian teratoma resulting in ovarian torsion
Axial T1 MRI without contrast of the pelvis (above left) shows a large, round, thick walled lesion in the middle of the pelvis that has some high signal intensity fat in its left wall. Axial (above right), coronal (below left), and sagittal (below right) T2 MRI show the mass is superior to the bladder, and its central aspect has high signal intensity and therefore is cystic. Several small peripheral cysts are seen within the lesion.

Radiology Cases of Immature Ovarian Teratoma