Radiology quiz

MARY BETH SCHMIDT, MD

aSpring 1998

HISTORY: A three-year-old previously healthy female had eight days of intermittent abdominal pain, nausea, vomiting, anorexia, diarrhea and fever. She was asymptomatic for four or five days followed by two days of recurrent symptoms. At presentation to the emergency department, she was afebrile with intermittent episodes of abdominal pain that caused her to cry and assume the fetal position. She slept comfortably between episodes. White blood cell count was normal. Urinalysis was essentially negative. Hemoglobin and platelets were slightly low. Stool was heme negative. Plain film of the abdomen was unremarkable. Physical exam revealed mid epigastric and left lower quadrant pain. An abdominal ultrasound was obtained.

QUESTION: What is your differential diagnosis at this point?

FIGURE 1. Longitudinal sonographic image through the left pelvis shows an enlarged left ovary (arrows) with peripheral small cysts (arrowheads); B = bladder.

FINDINGS: Ultrasound showed a small amount of free fluid in both lower quadrants. The left ovary (Figure 1) was enlarged; it measured about 4 cm in diameter with several small 5–6 mm peripheral cysts. Color and duplex Doppler scanning documented arterial and venous flow in the ovary as well as considerable surrounding vascularity. Right ovary and uterus were unremarkable.

FIGURE 2. A 10-year-old female has intermittent right pelvic pain and has the same diagnosis as the quiz patient. A prior CT showed a right adnexal mass and a small amount of free fluid in the pelvis. Transverse sonographic image of the midline pelvis shows an enlarged right ovary (arrows) with small internal cysts and a normal-appearing left ovary (arrowhead); B = bladder.

QUESTION: What is your most likely diagnosis now?

RESULT: The patient had an exploratory laparotomy. The right ovary appeared normal. A very congested and edematous left fallopian tube and ovary were found. The left fallopian tube and ovary were untwisted whereupon they became more pink and less congested. A left oophoropexy was performed.

Discussion

Adnexal torsion in girls with abdominal pain must be suspected. Although adnexal torsion is rare in childhood, it must be considered so that early diagnosis and treatment can be made before the adnexa become gangrenous.

Ovarian torsion is partial or complete rotation of the ovary on its vascular pedicle. This leads to arterial and venous flow compromise, ovarian parenchymal congestion, and possible hemorrhagic infarction. Ovarian torsion can occur in children with ovarian cysts and tumors which act as a fulcrum.¹ Torsion can also occur in normal adnexa. Children are known to have mobile normal adnexa during changes of intra-abdominal pressure or body position.² Torsion may involve the ovary, fallopian tube, or both. Adnexal torsion is usually unilateral.¹ It can be recurrent. Subsequent contralateral torsion has occurred as well.³ Prenatal ovarian torsion has also been reported.⁴

The typical presentation is nonspecific and includes abdominal pain, leukocytosis, nausea, vomiting, anorexia, diarrhea, or constipation. About half of the patients have had a similar episode in the past that resolved.¹ Half have a palpable mass.⁵ Fever is not common and may be seen in those patients with necrosis or abscess formation.

Sonography is very useful in evaluating and diagnosing pelvic pathology. The sonographic appearance of ovarian torsion is quite variable. Findings include free pelvic fluid, ovarian enlargement, and adnexal cysts and tumors. The enlarged ovary may have increased sound transmission. It may be solid or cystic. A relatively specific sign for ovarian torsion is multiple peripheral cysts in an enlarged ovary. These peripheral cysts may be due to movement of fluid into follicles secondary to vascular congestion. The absence of vascular flow is not specific for torsion since some adnexal masses may not have internal flow. Conversely, vascular flow presence does not rule out torsion. Flow in these cases may be secondary to the dual blood supply of the ovary or from venous thrombosis which causes symptoms before the loss of arterial flow.¹ Transvaginal sonography of the ovaries may provide further detail, but it is not useful in nonsexually active girls. Less often, CT or MRI can be used in the diagnosis of ovarian torsion.^6,7

Differential diagnoses based on clinical presentation includes appendicitis, intussusception, gastroenteritis, pyelonephritis, salpingitis, hernia, inflammatory bowel disease and Meckel's diverticulitis. Differential diagnosis based on sonography includes hemorrhagic ovarian cyst, ovarian mass or neoplasm, parovarian cyst, ectopic pregnancy, pelvic inflammatory disease, and abscess.

If the untwisted ovary is thought to be viable at the time of surgery, oophoropexy is performed. This procedure preserves the ovary and may reduce the incidence of recurrent torsion. Oophoropexy for the contralateral ovary to prevent its subsequent torsion has been advocated in recent literature.³ Childhood ovarian surgery is being performed laparoscopically in some centers.^{3, 8, 9}

In summary, we must suspect ovarian torsion in girls with abdominal pain. Prompt imaging and surgical intervention may salvage the adnexa.

REFERENCES

1. Siegel MJ (ed): Pediatric Sonography (ed 2), New York: Raven Press, 1995, 456–458.

2. Farrell TP, Boal DK, Teele RL, Ballantine TV: Acute torsion of normal uterine adnexa in children: Sonographic demonstration. AJR 1982;139:1223–25.

3. Nagel, TC, Sebastian J, Malo JW: Oophoropexy to prevent sequential or recurrent torsion. J Amer Assoc Gyn Laproscopists 1997;4(4):495–498.

4. Sherer DM, Shah YG, Eggers PC, Woods Jr JR: Prenatal sonographic diagnosis and subsequent management of fetal adnexal torsion. J Ultrasound Med 1990;9:161–163.

5. Graif M, Shalev J, Strauss S, Engelberg S, Mashiach S, Itzchak Y: Torsion of the ovary: Sonographic features. AJR 1984;143:1331–34.

6. Bellah RD, Griscom NT: Torsion of normal uterine adnexa before menarche: CT appearance. AJR 1989;152:123–124.

7. Bader, Ranner G, Haberlik A: Torsion of a normal adnexa in a premenarcheal girl: MRI findings. Eur Rad 1996;6(5):704–706.

8. Cohen Z, Shinhar D, Kopernik G, Mares AJ: The laparoscopic approach to uterine adnexal torsion in childhood. J Ped Surg 1996; 31(11):1557–59.

9. Davidoff AM, Hebra A, Kerr J, Stafford PW: Laparoscopic oophorectomy in children. J Lap Surg 1996;6(Suppl 1):S115–119.

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