TERATOMA

Teratomas are tumors comprising more than a single cell type derived from more than one germ layer. Teratomas range from benign, well-differentiated (mature) cystic lesions to those that are solid and malignant (immature). Additionally, teratomas may be monodermal and highly specialized, and, rarely within some mature teratomas, certain elements (most commonly squamous components) may undergo malignant transformation.
Mature cystic teratomas account for 10-20% of all ovarian neoplasms. Not only are they the most common ovarian germ cell tumor but also the most common ovarian neoplasm in patients younger than 20 years. They are bilateral in 8-15% of cases.

Complications of ovarian teratomas include torsion, rupture, infection, hemolytic anemia, and malignant degeneration.

Torsion is by far the most significant cause of morbidity, occurring in 3.2-16% of cases. Several series have demonstrated that increasing tumor size correlates with increased risk of torsion.

Rupture of a cystic teratoma is rare and may be spontaneous or associated with torsion. It occurs in approximately 1-4% of cases. Rupture may occur suddenly, leading to shock or hemorrhage with acute chemical peritonitis. Chronic leakage also may occur, with resultant granulomatous peritonitis. Prognosis after rupture usually is favorable, but the rupture often results in formation of dense adhesive disease. 
In its pure form, mature cystic teratoma of the ovary always is benign, but in approximately 0.1-2% of cases, it may undergo malignant transformation into one of its elements. The prognosis for patients with malignant degeneration is dismal, with 5-year survival rates reported in the range of 15-31%. The prognosis appears to be somewhat better if the malignant element is squamous rather than adenocarcinoma.

Mature cystic teratomas of the ovaries may be removed by simple cystectomy rather than salpingo-oophorectomy.


EMEDICINE