Prepubertal ovarian cyst formation: 5 years' experience

To document the frequency of ovarian cyst formation in the prepubertal female and to report on the clinical implications of these cysts.

We evaluated cases from a retrospective chart review of prepubertal females with ovarian cysts.

Over a 5-year period, 1818 ultrasound studies were completed in prepubertal females, from which 99 patients were identified as having ovarian cysts. The majority (82 of 99, 83%) were small, unilocular cysts averaging 2-3 mm in diameter. The incidence of these small cysts ranged at 2-5% in females between birth and age 8. Large ovarian cysts (ie, greater than 2 cm in diameter) are rare in young girls over age 2, with most occurring within the first year of life. Of the 17 large ovarian cysts, two presented with torsion and both were complex on ultrasound examination. Five (29%) of the large ovarian cysts were treated conservatively and demonstrated regression on follow-up; these were unilocular cysts. Although functioning cysts resulting in precocious pseudopuberty are expected to be rare, we identified five cases (5%) in our series.

Small, unilocular ovarian cysts less than 1 cm in diameter are found in prepubertal females with a frequency of 2-5% and are clinically insignificant. Ovarian cysts greater than 2 cm are rare. Unilocular ovarian cysts less than 5 cm may be followed conservatively with ultrasound surveillance until regression, without a major risk of torsion. Ovarian cysts associated with precocious pseudopuberty are generally larger than 2 cm and may be recurrent.