Pediatric and Adolescent Ovarian Torsion
BY JENNIFER ENG-LUNT, M.D., HEATHER APPELBAUM, M.D., AND JAHN AVARELLO, M.D.
Ovarian torsion is an infrequent diagnosis in the pediatric age group. The clinical picture is nonspecific, and children cannot always articulate their symptoms, which often makes the diagnosis a challenge. However, early recognition and prompt management yield significant reduction in morbidity and an increased likelihood of ovarian salvage. Emergency physicians must always consider this differential in pediatric and adolescent females presenting with abdominal pain. We offer an evidence-based approach to the diagnosis and management of ovarian torsion in the pediatric population.
Adnexal torsion occurs primarily in the child-bearing age group, but it is not uncommon in premenarchal girls. According to Shalev et al. (1985), gonadal torsion is of particular concern in perimenarchal girls. The actual incidence of ovarian torsion in children is not well defined and varies in recent literature. Studies have found an estimated incidence of 4.9 per 100,000 among females 1-20 years old1 and a diagnosis in up to 2.7% of cases presenting with acute abdominal pain.2 In one 16-year study, excluding neonates, the mean age was found to be 12.5 years, ranging from 8 to 16 years old.3 However, other similar studies have shown the mean age to be around 9.5 years old.4
Delay and misdiagnosis of adnexal torsion is common and may result in loss of the ovary, fallopian tube, or both.5 An incidental finding of an isolated absence of an ovary or fallopian tube may be the result of an undiagnosed previous adnexal torsion.5 Early diagnosis of ovarian torsion is paramount and will reduce the risk of complications and increase the probability of ovarian preservation. Diagnostic laparoscopy is the gold standard for diagnosing ovarian torsion. Current reports show an 80%-90% rate of ovarian salvage with early surgical intervention.6
Ovarian torsion occurs secondary to the abnormal twisting of the involved ovary on its ligamentous support. Torsion of the ovarian blood supply will result in venous congestion, hemorrhage, and eventually ischemia. Prolonged ischemia of the ovary or other adnexal structures can lead to necrosis, resulting in loss of ovarian function or infection and peritonitis.7
The anatomy is such that the right side is more frequently affected than the left. In pediatric patients, ovarian torsion can be caused by a variety of anatomic mechanisms. Most studies have found approximately 50% of ovarian torsion in pediatric patients to involve adnexal cysts, teratomas, or other benign masses, including polycystic ovaries.6,8 Most data suggest that the risk is higher for cysts larger than 4-5 cm, but there have been case reports of cysts less than 5 cm causing symptoms.10-12 Another risk for ovarian torsion is a malignant tumor; however, there is only a 1.8% malignancy rate reported in the literature.13 Thus, it is important to note that a large number of cases of adnexal torsion may occur with anatomically normal ovaries.
Proposed mechanisms that may increase risk of ovarian torsion in a normal ovary include:
Disproportionately elongated utero-ovarian ligament that allows excessive ovarian movements.
Jarring movements of a relatively large ovary in a small infant.14,15
Associated Müllerian anomalies.
The diagnosis of adnexal torsion in young girls presents a diagnostic challenge because the presenting signs and symptoms of ovarian torsion are nonspecific and may mimic constipation, gastroenteritis, mesenteric adenitis, appendicitis, renal colic, pelvic inflammatory disease, ectopic pregnancy, and hemorrhagic or ruptured ovarian cysts.
The most common presenting symptoms are abdominal pain, nausea, and vomiting. Classically, the pain is acute in onset and colicky in nature. The most common physical exam findings in children with ovarian torsion are tenderness, adnexal fullness or mass, and fever. However, up to 50% of pediatric patients with ovarian torsion may have variable symptoms or lack specific physical exam findings altogether, with 30% having only mild pain and 30% with no pain. Peritoneal findings are infrequent, and the absence of rebound or guarding does not correlate with the severity of compromise to ovarian vascular supply. When evaluating infants and younger children, it is often helpful to perform an abdominal exam while distracting them or even when they are sleeping so as to differentiate abdominal tenderness from crying because of fear of the practitioner. Even with the appropriate symptoms, physical exam findings can also be very subtle and quite variable. Accordingly, a high index of suspicion for adnexal torsion is imperative in any girl presenting with lower abdominal pain.
When compared with patients with acute appendicitis, the only occasionally helpful exam finding in these patients was the palpation of an abdominal mass. Yet studies show that such a finding is reported in fewer than 10% of torsion cases. Researchers have yet to find statistically distinguishing variables, thus making ovarian torsion a diagnostic challenge for even the more experienced clinicians.16,17,19
A wide differential diagnosis should be kept in mind, and tests should be tailored both to rule out other diagnoses and to rule in the diagnosis of ovarian torsion.
The differential diagnosis often consists of the following:
Hemorrhagic/ruptured ovarian cyst
Pelvic inflammatory disease
A comprehensive approach must be taken to diagnose ovarian torsion. Laboratory tests will not diagnose ovarian torsion but will augment the clinical evaluation of a young female presenting with abdominal pain. Urinalysis, serum HCG, and complete blood count are all useful tests for evaluating other causes of acute abdominal pain.
Pelvic ultrasound is the primary imaging modality in suspected ovarian torsion in children and peripubertal adolescents. In patients whose clinical presentation does not dictate immediate surgical intervention, ultrasound should be performed expeditiously. As young children and some adolescents cannot undergo transvaginal ultrasound, it is important for the patient to have a full bladder to maximize the chance of visualizing the ovaries on a transabdominal ultrasound.The most common abnormal finding on ultrasound is an enlarged, heterogeneous-appearing ovary. Other studies have suggested that enlarged ovaries that cross the midline are associated with adnexal torsion.
However, because up to 34% of cases of torsion have normal sonographic appearance of the ovaries, pelvic ultrasound can play an important role in guiding the management of ovarian torsion and should be used as an adjunct to the history and physical examination. The addition of color Doppler ultrasound has not been found to improve diagnostic accuracy. It should be noted that the presence of blood flow on Doppler ultrasound does not rule out ovarian torsion. One pediatric study found that 64% of known ovarian torsions had blood flow on color Doppler.16-22
MRI and CT can also reliably detect ovarian lesions and have been recommended as adjunctive diagnostic modalities. One case study found MRI to be helpful in diagnosing early ovarian torsion by identifying a twisted pedicle that was missed on ultrasound.23 When transabdominal pelvic ultrasound is unable to define a diagnosis, MRI may reveal a predominantly hyperintense signal containing small areas with hypointense lesions in T2-weighted images, a potential sign of hemorrhagic infarction.17 However, the accuracy of MRI and CT varies in the literature and has yet to be validated. In general, abnormal ovarian size or masses may be detected by either modality. MRI and CT have not been found to provide any significant advantage when combined with ultrasound versus ultrasound alone, and may delay necessary surgical intervention.
Therefore, MRI and CT should be reserved for those cases where ovarian pathology is highly suspected but ultrasound is equivocal.19-22
CT scanning can be used to reveal an enlarged right adnexa with thickened tubular structure indicative of twisted vascular pedicle (image 1) and a enlarged, engorged midline right ovary with surrounding free fluid (image 2).
Another CT scan revealed a simple-appearing cyst that is actually an edematous vacuole in a torted ovary. Note the loss of follicles and loss of normal-appearing parenchyma in this scan (image 3), compared with a normal ovary (image 4).
MRI demonstrated an enlarged and edematous left ovary in an ectopic location (midline), with numerous peripheral follicles and free fluid in the pelvis (image 5).
Upon recognition of signs and symptoms of suspected ovarian torsion, an expeditious consultation with a pediatric gynecologist (where available) or pediatric surgeon should be done during the early stages of the evaluation in order to facilitate swift management in a young girl with a suspected diagnosis of adnexal torsion.19
The mainstay of treatment is diagnostic laporoscopy with detorsion of the ovary. Historically, oophorectomy was the standard treatment of the torsed ovary. However, more recent publications have reevaluated ovarian preservation with favorable results. Detorsion is now recommended in lieu of oophorectomy, and there is little evidence of accompanying increases in morbidity as once believed.6
Urgent surgical evaluation must be emphasized. Better outcomes have been shown if surgical intervention occurs within 36 hours of ovarian torsion.20,21
Oophoropexy is also widely debated in the literature, and there are no trials evaluating its efficacy. Oophoropexy can be offered as an option to prevent castration in cases of repeat ovarian torsion or in cases of bilateral adnexal torsion.22,23
Ovarian torsion in the pediatric patient is an infrequent but important finding carrying potential for high morbidity if missed. The examination is often misleading, and 30% of patients have no pain on presentation but an otherwise suggestive history.
An ultrasound evaluation should be done as soon as possible, but it is important to remember that the presence of blood flow using Doppler ultrasound does not rule out the diagnosis and that up to 34% of ovarian torsions have a normal sonographic appearance of the ovaries.
The emergency physician should be cognizant of the variability in presentation and advocate for prompt intervention when the patient's history suggests the diagnosis.
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