What is a dermoid cyst (mature cystic teratoma)?

A dermoid cyst (mature cystic teratoma) is the commonest benign germ cell tumour, common in young women.

It arises from pluripotent germ cells and contains tissues from all three germ layers (ectoderm, mesoderm, endoderm) - so it may contain hair, skin, teeth, sebaceous material, and even thyroid tissue. It is benign but can undergo torsion (it is often a cause of ovarian torsion).

Clinical relevance. Recognising the dermoid cyst (commonest benign germ cell tumour, all 3 germ layers, torsion risk) informs diagnosis and management in young women.

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Dermoid cyst (mature cystic teratoma)

The dermoid cyst is the commonest benign germ cell tumour.

What it is

• The commonest benign germ cell tumour of the ovary, common in young women (reproductive age).
• Arises from pluripotent germ cells (primitive germ cells).

Contents

• Contains tissue derived from all three germ cell layers - ectoderm, mesoderm, and endoderm.
• So it may contain hair, skin, sebaceous material, teeth, cartilage/bone, and even thyroid tissue (struma ovarii).

Behaviour

• Benign; often asymptomatic and found incidentally.
• Can undergo complications - especially torsion (a common cause of ovarian torsion), and rarely rupture (chemical peritonitis) or malignant change.
• Can be bilateral in a minority.

Management

• Cystectomy (ovarian-sparing where possible), particularly in young women.