Dermoid cyst teratoma
Dermoid cyst teratomas (aka mature cystic teratomas) – a teratoma – is the most common type of ovarian neoplasm. Dermoid cysts account for two-thirds of ovarian tumours in children under the age of 15, and most are diagnosed at ages of 20-40. Some are asymptomatic and incidental findings in radiographs of the pelvis. Complications include torsion, infection, perforation into the peritoneal cavity or a pelvic organ, and hemolytic anemia.
On gross examination, dermoid cysts are ovoid or globular and the surface is smooth and white to gray. Fifteen percent are bilateral. On bisection, the typical case has a single cyst that contains yellowish sebaceous material and hair and there is an intra-cystic protuberance (the mamilla, or Rokitansky's tubercle) in which various tissues are seen.
Microscopically, mature cystic teratomas are composed of adult-type tissues, usually representing all three germ layers. Commonly present are epidermis, skin appendages, brain, muscle, bone, teeth, cartilage, fat, respiratory and gastrointestinal epithelium, and thyroid.
Dermoid cysts are benign and most can be resected with conservation of adjacent ovarian tissue. Secondary malignant tumours (usually squamous cell carcinoma) rarely occur in mature cystic teratomas in older women.