a brief overview of ovarian germ cell tumors

1. GERM CELL TUMOURS OF
THE OVARY

2. • Introduction
• Teratomas
• Dysgerminoma
• Yolksac tumour
• Choriocarcionoma
• Others
• Conclusion

3. Introduction
• Germ cell tumors constitute 15% to 20% of all ovarian tumors
• Most are benign cystic teratomas.
• Others, found principally in children and young adults, may show malignant
behavior and pose problems in histologic diagnosis and in therapy

6. TERATOMA
• Teratomas are divided into three categories:
(1) mature (benign)
(2) immature (malignant), and
(3) monodermal or highly specialized.

7. 1. Mature (Benign) Teratomas
 Most benign teratomas are cystic and are often referred to as dermoid cysts,
because they are almost always lined by skin-like structures
 usually found in young women during the active reproductive years
MORPHOLOGY
GROSS
• Benign teratomas are bilateral in 10% to 15% of cases.
• Are characteristically uniocular
• Can contain: cartilage, bone, tooth structure, hair and sebaceous material.

8. • Microscopically: the cyst wall is
composed of stratified squamous
epithelium with underlying
sebaceous glands, hair shafts, and
other skin adnexal structures
• Can also include cartilage, bone,
thyroid, and neural tissue
• About 1% of the dermoids undergo
malignant transformation, most
commonly to squamous cell
carcinoma

9. 2. Immature Malignant Teratomas
• These are rare tumors
• differ from benign teratomas in that the component tissues resemble embryonal
and immature fetal tissue.
• The tumor is found chiefly in prepubertal adolescents and young women, the
mean age being 18 years.

10. • Morphology
Gross; Hair, sebaceous material,
cartilage, bone, and calcification may
be present, along with areas of
necrosis and hemorrhage.
Microscopy; there are varying
amounts of immature neuroepithelium,
cartilage, bone, muscle, and other
elements.

11. 3. Monodermal or Specialized Teratomas
• The specialized teratomas are a remarkable, rare group of tumors, the most
common of which are struma ovarii and carcinoid
• They are always unilateral
• Struma ovarii; is composed entirely of mature thyroid tissue, which may be
functional and cause hyperthyroidism
• The ovarian carcinoid; which presumably arises from intestinal tissue found in
teratomas
• if large (>7cm) they can produce sufficient 5-hydroxytryptamine(serotonin) to
cause the carcinoid syndrome

12. • Primary ovarian carcinoid must be distinguished from metastatic intestinal
carcinoid, which is virtually always bilateral.
• Even rarer is the strumal carcinoid

13. Dysgerminoma
• Dysgerminoma is the ovarian counterpart of testicular seminoma
• 2% of ovarian cancers and roughly 50% of malignant ovarian germ cell tumors
• They may occur in childhood, but 75% occur in the second and third decades.
• A few produce elevated levels of chorionic gonadotropin, a finding that correlates
with the presence of syncytiotrophoblastic giant cells. Also secrete LDH

14. • dysgerminomas express OCT-3, OCT4, and NANOG.
• They also express the receptor tyrosine kinase KIT
• These proteins are useful diagnostic markers and, in the case of KIT, may also
serve as a therapeutic target
• All are malignant, but the degree of histologic atypia is variable, and only about
one third are aggressive
• These neoplasms are responsive to chemotherapy, and even those that have
extended beyond the ovary can often be cured. Overall survival exceeds 80%.
Also highly responsive to radiotherapy

15. • MORPHOLOGY
• Most dysgerminomas (80% to 90%) are
unilateral tumors ranging in size from barely
visible nodules to masses that virtually
fill the entire abdomen. On cut
surface they have a solid yellow-white to
gray-pink appearance.
• Like seminoma, it is composed of large
vesicular cells having a clear
cytoplasm, well-defined cell boundaries,
and centrally placed regular nuclei. The
tumor cells grow in sheets or cords
separated by scant fibrous stroma, which
is infiltrated by mature lymphocytes
and may contain occasional granulomas.

16. Yolk Sac Tumor (endodermal sinus tumor)
• The second most common malignant tumor of germ cell origin
• Derived from malignant germ cells that are differentiating along the
extraembryonic yolk sac lineage .
• The tumor cells elaborate α-fetoprotein
• Its characteristic histologic feature is a glomerulus-like structure composed of a
central blood vessel enveloped by tumor cells within a space that is also lined by
tumor cells (Schiller-Duval body)

17. Most patients are children or young women
presenting with abdominal pain and a
rapidly growing pelvic mass that usually
appears to involve a single ovary. With
combination chemotherapy, there is greater
than 80% survival independent of disease
stage.
•
A Schiller-Duval body in yolk sac carcinoma

18. Choriocarcinoma
• More commonly of placental origin, choriocarcinoma, like the yolk sac tumor, is
an example of extraembryonic differentiation of malignant germ cells
• Most ovarian choriocarcinomas exist in combination with other germ cell tumors,
and pure choriocarcinoma is extremely rare.
• They are histologically identical to the more common placental lesions

19. • The ovarian tumors are aggressive and have usually metastasized
hematogenously to the lungs, liver, bone, and other sites by the time of diagnosis
• Like all choriocarcinomas they elaborate high levels of chorionic gonadotropins
• In contrast to choriocarcinomas arising in placental tissue, those arising in the
ovary are generally unresponsive to chemotherapy and are often fatal

20. other Germ Cell Tumors
• Embryonal carcinoma
• Polyembryoma
• Mixed germ cell tumors

21. Conclusion
• Germ cell tumors constitute 15% to 20% of ovarian tumors. Germcell
tumors show various lines of differentiation toward oogonia
(dysgerminoma), extraembryonic yolk sac (yolk sac tumors),
placenta(choriocarcinoma), or multiple germ layers (teratoma).