Ovarian yolk sac tumor
Ovarian yolk sac tumors, also known as endodermal sinus tumors, are a type of ovarian germ cell tumors.
Epidemiology
Ovarian yolk sac tumor is a rare malignant ovarian germ cell tumor that usually occurs around the second decade of life. It is considered the most common malignant germ cell tumor of the ovary in children . The overall occurrence is rare, however.
Pathology
They are typically well-encapsulated round to oval masses.
Associations
- occasionally an ovarian yolk sac tumor can arise from a pre-existing ovarian dermoid cyst
Markers
- affected patients have an elevated serum tumor marker AFP
Radiographic features
Typically, yolk sac tumors manifest as a large, complex pelvic mass that extends into the abdomen and contains both solid and cystic components. The cystic areas are composed of epithelial lined cysts produced by the tumor or of co-existing mature teratomas. Bilaterality is rare.
Ultrasound
Tends to have both echogenic and hypoechoic components .
MRI
They can be associated with prominent signal voids on MRI . Areas of hemorrhage can also be seen.
Treatment and prognosis
These tumors tend to grow rapidly and had a poor prognosis in the past, but now the prognosis has improved with the use of new therapies (platin or carboplatin, etoposide, bleomycin). Early lymphatic spread, as well as invasion, is common.