Are ovarian teratomas (mature cystic teratomas) benign?

From the Guidelines

Most ovarian teratoma cysts are benign, with approximately 99% being non-cancerous and accounting for about 20% of all ovarian tumors. These growths, also called dermoid cysts, develop from germ cells and can contain various types of tissue including hair, skin, teeth, bone, and even thyroid tissue. According to a recent study by Gupta et al 1, the risk of malignancy in these classic “benign”-appearing lesions is < 1% in a cohort of 970 average-risk women.

Key Characteristics of Ovarian Teratoma Cysts

• They are typically non-cancerous and slow-growing
• They can contain various types of tissue, including hair, skin, teeth, bone, and thyroid tissue
• They account for about 20% of all ovarian tumors
• The vast majority (approximately 99%) are benign, with a small percentage being malignant, particularly in older women or when the teratoma is immature

Management and Treatment

• Treatment typically involves surgical removal of the cyst while preserving the ovary when possible
• Regular gynecological check-ups with ultrasound monitoring are important for women diagnosed with these cysts to ensure they remain benign and don't cause complications
• Discussing the specific characteristics of the cyst with a healthcare provider is essential for appropriate management, as noted in the study by Parazzini et al 1

Risk of Malignancy

• The risk of malignancy in unilocular cysts is very low, with a recent meta-analysis by Parazzini et al 1 demonstrating a risk of malignancy of 0.6% in 987 unilocular cysts removed surgically in premenopausal women
• The risk of malignancy in benign-appearing lesions on US managed conservatively with 2-year follow-up was 0.3% to 0.4% for malignancy and 0.2% to 0.4% for acute complications such as torsion or cyst rupture, as reported by Valentin et al 1

From the Research

Ovarian Teratoma Cysts

• Ovarian teratoma cysts are typically benign, with malignant transformation occurring in approximately 2% of cases 2.
• Benign cystic teratoma is one of the most common benign tumors of the ovary, representing between 44 and 62% of all ovarian tumors diagnosed in women younger than 40 years 3.
• The most frequent complication of benign mature teratomas is torsion, which occurs in 3.5% of cases 4.

Treatment and Management

• Laparoscopic approach to teratomas is a safe and efficient procedure, with less bleeding and shorter hospital stay compared to laparotomy approach 3.
• Conservative laparoscopic management of ovarian teratoma torsion, including untwisting of the adnexa and cystectomy, is a viable option for young women who want to preserve their fertility 5.
• Early diagnosis and treatment of mature ovarian cystic teratoma are essential to prevent complications such as torsion, rupture, internal hemorrhage, and malignant transformation 6.

Characteristics and Incidence

• Mature cystic teratoma of the ovary (MCTO) is frequent in women of reproductive age 2.
• Ovarian teratoma cysts can occur in different age groups and can appear in various sizes, with some cases presenting as extremely large tumors 6.
• Torsion of the teratoma is more likely to occur with benign rather than malignant tumors 2.