It’s a well-established fact that an ovarian dermoid cyst or teratoma can turn into cancer.

The malignant transformation of these ovarian cysts is much more likely to occur in women over 50, but can also happen in younger women.

However, 80 percent of the diagnoses of these cysts occur in premenopausal women — and this may actually be why most malignant transformations end up being diagnosed in postmenopausal women.

Type of Ovarian Cyst that
Can Turn into Cancer

It’s the dermoid cyst, also called a teratoma or mature cystic teratoma (MCT).

These benign cysts originate from germ or embryonic cells and thus contain different kinds of tissue such as cartilage, bone and skin.

Over 80 percent of MCTs develop during reproductive years. A woman may go her entire life without ever knowing she has one of these.

The discovery is made when the cyst gets big enough to cause symptoms, namely abdominal discomfort, and a woman thus undergoes a diagnostic ultrasound.

The ovarian cyst may also be discovered by accident, when a woman undergoes an ultrasound for an unrelated reason such as pregnancy.

Why You Should Not Panic
that Your Dermoid Ovarian Cyst
Will Turn into Cancer

Studies across the board affirm that malignant transformation is rare.

Though most cases of ovarian cysts that turn into cancer occur in women over 50, this “most” is relative to the number of cancer transformations in younger women. Overall, the malignant transformation rate is rare.

How rare? panic
The Journal of Case Reports Pathology (2012, Mandal et al) states:

The omentum is a membrane that connects the stomach with other organs.

To put the rarity of this cancer another way, Case Reports in Obstetrics and Gynecology (2017, Jitsumori et al) cites the following data:

• In one study (Peterson et al), the mature dermoid ovarian cysts turned into cancer in 1.8% of 8,000 patients.

• The rate was reported to be one to two percent by Hurwitz et al.

• Kim et al reported a rate of four out of 560 patients (0.6%). The cancer was discovered when these patients underwent surgery for their teratomas at Dr. Hurwitz’s facility.

As mentioned earlier, most cancer transformations of ovarian dermoid cysts happen in women over 50. But this isn’t believed to be due to a weaker, aging body.

Obstetrics & Gynecology Science (2015, Park et al) points out that most MCTs may be found 15 to 20 years prior to turning into cancer, and that “it is possible that prolonged exposure to various carcinogens in the pelvic cavity might lead to malignant transformation,” says the paper.

“Therefore, malignant transformation typically occurs in postmenopausal women.”

The Jutsimori et al paper says the time span between discovery of the MCT and eventual cancer transformation is at least 10 years.

Risks of Ovarian Cyst
Turning into Cancer

For MCTs, there are several suspected risk factors (no particular order):
• HPV infection
• Elevated CA-125
• Older age
• Large cysts panic

Because there’s a big time lag between when these ovarian cysts turn into cancer, it’s recommended that women, who’ve already been diagnosed with an MCT, undergo continuous surveillance and be informed of the possibility of malignant transformation – even though it is rare.

Sources: 
sciencedirect.com/science/article/pii/S1470204508703061
onlinelibrary.wiley.com/doi/full/10.1111/j.1525-1438.2006.00285.x
ncbi.nlm.nih.gov/pmc/articles/PMC5540728/
ncbi.nlm.nih.gov/pmc/articles/PMC4663225/
ncbi.nlm.nih.gov/pmc/articles/PMC3469088/
hindawi.com/journals/criog/2017/2947927/ ovarian cyst turn into cancer, should you panic