A Pediatric Radiology Textbook and Pediatric Radiology Digital Library
Pediatric Ovarian Torsion
Etiology: — Twisting of ovarian pedicle due to excessive mobility of adnexa in prepubertal girls resulting in decreased arterial blood flow — Mass can act as lead point (cyst or tumor)
Imaging: — Asymmetric size is most sensitive finding as on average the torsed ovary is 12 times larger than contralateral ovary — Ovaries are medial to normal location in 1/3 of patients — Color flow present to ovaries in 2/3 of patients with ovarian torsion so if you rely on lack of flow a lot of torsion will be missed — Absent Doppler flow to ovary is nonspecific as 1/3 of normal controls in a study had absent flow — Twisted fallopian tube (whirlpool sign) is highly specific for ovarian torsion but is challenging to visualize
Imaging summary: — Echogenic stroma with peripheralized follicles — Medialized ovary — Very big ovary (adnexal volume greater than 20 ml) — Twisted adnexa
Imaging US: — Asymmetric enlargement (often greater than 4 centimeters in size) or size discrepancy (consider torsion when ovarian volume greater than 3 times opposite normal side) – this is most sensitive sign of ovarian torsion — Prominent peripheral follicles — Displacement from normal adnexal location (ovary located medial to mid-uterine line in transverse plane or superior to uterus) — bsent parenchymal blood flow (unreliable as ovary has dual blood supply from ovarian and uterine arteries)
Imaging US pitfalls: — Doppler flow not reliable and presence of Doppler flow does not rule out torsion — Difficult to obtain spectral waveforms in tiny ovaries or large patients — Under distended urinary bladder
Imaging CT: — Asymmetric enlargement of ovary — Displacement of ovary — Twisting of pedicle — Subacute ovarian hemorrhage — Periovarian soft tissue edema — Eecreased enhancement
Imaging MRI: — Asymmetric enlargement of ovary — Peripherally displaced follicles which may be hemorrhagic with increased T1WI signal — Displacement of ovary — Twisting of pedicle — Subacute ovarian hemorrhage — Periovarian soft tissue edema — Decreased enhancement
Note: You will be lucky to have only a 40% false positive rate, if you are right 100% of the time you are missing torsion
DDX: Fallopian tube torsion
Complications: Infarcted ovary
Treatment: Surgical
Clinical: — 3% of all cases of acute abdominal pain in children — Affects females of reproductive age and younger — Can occur throughout childhood with 2 peaks in infancy and around menarche (~ 12 years) — Abdominal pain only consistent symptom – right much more than left and acute onset with nausea and vomiting or indolent with weeks of intermittent pelvic pain
Radiology Cases of Ovarian Torsion
Sagittal US of the pelvis (above left) shows an enlarged right ovary with multiple peripheral follicles. Axial CT with contrast of the abdomen (above right) shows the right ovary to be enlarged with multiple peripheral follicles and to be malpositioned in the midline of the pelvis while the coronal CT (below) shows the right ovary to be in a position in the midline above the bladder.
Radiology Cases of Ovarian Torsion Due to Neonatal Ovarian Cyst
T1 coronal (left) and T1 sagittal (right) and T2 axial (below) MRI images show a heterogeneous intraperitoneal mass that appears to have hemorrhagic and calcified components. In the operating room this mass was found to be torsed.Transverse US of the fetus (above) shows an anechoic mass in the left side of the abdomen anteriorly. Post natal sagittal US images of the mass (below) show the mass to have mixed cystic and solid components.
Radiology Cases of Ovarian Torsion Due to Ovarian Cyst
Sagittal grayscale US of the right ovary (above) shows the right ovary to be enlarged and to contain a large central hypoechoic cyst. The right ovary was 4 times larger in size than the normal left ovary. Sagittal spectral doppler US of the right ovary (below) shows arterial flow to be present in the right ovary, but the amount of arterial flow was decreased when compared to the arterial flow to the left ovary.
Radiology Cases of Ovarian Torsion Due to Mature Ovarian Teratoma
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.
Radiology Cases of Ovarian Torsion Due to Ovarian Dysgerminoma
Transverse and sagittal US of the pelvis (above) shows an echogenic and inhomgenous solid mass superior to the bladder. Neither ovary could be visualized. Axial CT with contrast of the abdomen shows a solid non-enhancing midline mass.
Surgery Cases of Normal Ovary
Surgical image after resection of a torsed right ovary shows a normal left ovary (which is white) in the midline just above the retractor.
Surgery Cases of Ovarian Torsion
Surgical image (above) shows the enlarged and purple in color right ovary twisted 360 degrees upon its pedicle. Surgical image (below) shows the right ovary to be enlarged and purple (upper right of image) while the normal left ovary is small in size and white (middle of the image).
Surgery Cases of Ovarian Torsion Due to Neonatal Ovarian Cyst
Surgical image shows a large circular and soft mass that was adherent to, but not invading, the hepatic flexure, omentum, and distal ileum and which was no longer connected to any pelvic structures. There was no ovarian tissue in the right adnexa. The left ovary was normal.
Surgery Cases of Ovarian Torsion Due to Ovarian Cyst
Surgical laparoscopic image (above) shows an enlarged grayish-white necrotic appearing right ovary in the midline of the pelvis in the center of the image. Upon closer inspection (below) the pedicle of the right ovary is seen to be twisted.
Surgery Cases of Ovarian Torsion Due to Ovarian Dysgerminoma
Surgical image (above) shows a mass arising from the left ovary. Surgical image (below) shows the left adnexal pedicle to be twisted in the center of the image. The mass and the left ovary and the fallopian tube were found to be torsed.
Gross Pathology of Ovarian Torsion
Gross Pathology of Ovarian Torsion Due to Neonatal Ovarian Cyst
Gross pathological image (above) shows the mass to be circular and cystic. Upon sectioning, the thin-walled cyst was filled with hemorrhagic, fibrinous material (below). Solid areas were not present.Gross pathological image shows the mass to be circular and cystic (above). Upon sectioning, the thin-walled cyst was filled with hemorrhagic and fibrinous material (below).
Gross Pathology of Ovarian Torsion Due to Ovarian Dysgerminoma
The surgical specimen measured 11 x 8 x 5 cm in size and was oval in shape with a tan outer surface. The lesion was soft but solid with extensive hemorrhage and necrosis. Gross pathological image of the cut specimen shows extensive hemorrhage and necrosis.
Histopathology Cases of Ovarian Torsion
Histopathology Cases of Ovarian Torsion Due to Neonatal Ovarian Cyst
Histopathological image H&E stained section shows a fibrous-walled cyst with few inflammatory cells and blood vessels filled with acellular fibrin; residual ovarian tissue was not identified.
Histopathology Cases of Ovarian Torsion Due to Ovarian Dysgerminoma
Histopathological image H&E stained section shows a largely necrotic tumor comprised of sheets of relatively uniform cells and scattered lymphocytes. Around rare blood vessels, a few viable neoplastic cells were characterized by prominent nucleoli and abundant cytoplasm.Histopathological image H&E stained section shows a largely necrotic tumor comprised of sheets of relatively uniform cells and scattered lymphocytes. Around rare blood vessels, a few viable neoplastic cells were characterized by prominent nucleoli and abundant cytoplasm.Histopathological image H&E stained section shows the uniformity of the neoplastic cells with prominent nucleoli and abundant, clear cytoplasm; scattered small clusters of lymphocytes are present.
