Massive luteinized follicular cyst of pregnancy.

Background: A large luteinized follicular cyst can rupture or twist during pregnancy. However, in the absence of those complications a simple ovarian cyst can often be managed conservatively, provided that sonographic evaluation of the cyst is benign. Rapid growth of a simple follicular cyst is rare but may occasionally complicate pregnancy.

Case: A 25-year-old primigravida had a simple-appearing adnexal mass detected by sonogram early in pregnancy. She was followed with serial sonograms. Because of the clear sonolucent appearance of the mass and the patient's preference, a conservative management was elected. The cyst grew in size as her pregnancy progressed, became symptomatic, and necessitated surgical intervention. Cystectomy and cesarean delivery at 36+ weeks relieved the symptoms and achieved delivery of a healthy infant.

Conclusion: Solitary luteinized follicular cysts of pregnancy have the potential to grow to a very large size and create complications related to their size alone. Conservative management of simple adnexal cysts in pregnancy, based on their sonographic appearance, can avoid risks of abdominal surgery in the second trimester of pregnancy, but in the third trimester, a large cyst can create significant complications requiring surgical intervention.