Dermoidal cysts commonly develop during the reproductive years. The traditional treatment for these cysts has been surgical intervention; however, this treatment can impair fertility. Caspi and associates designed a study that used ultrasound scanning as a way to follow patients with dermoid cysts that were 6 cm or smaller.

The diagnosis of dermoid cyst was determined by the presence of one of three unique pathognomonic features. The study observed 86 women who had an ovarian dermoid cyst no larger than 6 cm who were followed with ultrasound examination at three and nine months, and then annually.

The results of the study indicated that the average annual growth rate of ovarian dermoid cysts for premenopausal women was 1.77 cm. In postmenopausal women the average annual growth rate was -1.59 cm. When compared to zero, the premenopausal growth rate was significant; the postmenopausal growth rate was not. Of the patients who entered the study, 24 (28 percent) had surgery to remove the cyst, 21 of whom underwent surgery because the growth rate was over 2 cm per year. During the study, 28 women (32 percent) conceived while a cyst was present. There was no cyst torsion or malignant transformation in any of the patients during the follow-up period.

The authors conclude that dermoid cysts no larger than 6 cm can be managed conservatively with ultrasound scanning, provided the annual growth rate does not exceed 2 cm. The growth rate of these cysts tends to be slow, and complication rates are low. This management strategy allows women who are planning families an opportunity to observe dermoid cysts and postpone surgical intervention that could impair fertility. These cysts can also be observed in postmenopausal women, because the growth rate is slow and the cyst may actually decrease in size.