ovary

Fifth stage

Gynecology
Lec-

9/5/2017

Germ cell tumor

Origin : cells derived form oocytes

Incidence: 15- 20% of all ovarian tumors, 5% malignant
Age: young age

Agerm cell tumor (GCT) isaneoplasmderived fromgerm cells. Germ cells normally occur inside thegonads (ovaryandtestis). Germ cell tumors that originate outside the gonads may bebirth defectsresulting from errors duringdevelopmentofdevelopmentoftheembryo.

Etiology

Some investigators suggest that thisdistribution arises as a consequence of abnormal migration of germ cells duringembryogenesis. Others hypothesize a widespread distribution of germ cells tomultiple sites during normal embryogenesis, with these cells conveying geneticinformation or providing regulatory functions at somatic sites.

Classification

Germ cell tumors are classified by theirhistology,regardlessof location in the body.


Dysgerminoma
Incidence : very common
Age : 20 – 20 yrs
Bilateral : 10 – 15 %
Macroscopic features :
Solid tumors, elastic rubbery consistency having smooth, firm capsule

Teratoma

Derived from cells of all three germ layers
Types:
Mature or benign type (e.g. Dermoid cysts)
Immature or malignant type (e.g. Solid Teratoma)
Monodermal or highly specialized (e.g. Struma ovarii)

Choriocarcinoma and Embryonal Cell Carcinoma

Choriocarcinoma mostly of placental origin occurs in prepubertal girls. Highly malignant
Contains syncytiotrophoblasts and cytotrophoblasts
Secretes large quantities of the tumor marker - HCG
Embryonal cell carcinoma
Incidence : rare
Highly malignant


Ovarian Fibroma:
Meig’s syndrome
Ascites
Right sided effusion

Germ cell tumors are broadly divided intwo classes:

Thegerminomatousorseminomatousgermcell tumors (GGCT, SGCT) include onlygerminomaandits synonymsdysgerminomaandseminoma.
Thenongerminomatousornonseminomatousgermcell tumors (NGGCT, NSGCT) include all other germ cell tumors, pure and mixed.

The two classes reflect an importantclinical difference. Compared to germinomatous tumors, nongerminomatous tumorstend to grow faster, have an earlier mean age at time of diagnosis (~25 yearsversus ~35 years, in the case oftesticular cancers), and have a lower 5 year survival rate. The survival rate for germinomatoustumors is higher in part because these tumors are exquisitely sensitive toradiation, and they also respond well to chemotherapy. The prognosis fornongerminomatous has improved dramatically, however, due to the use ofplatinum-based chemotherapy regimens.

Mixed

Mixed germ cell tumors occur in manyforms. Among these, a common form is teratoma with endodermal sinus tumor.
Teratocarcinomarefers to a germ cell tumor that is a mixture ofteratomawithembryonal carcinoma, orwithchoriocarcinoma, orwith both.This kind of mixed germ cell tumor may be known simply as a teratomawith elements of embryonal carcinoma or choriocarcinoma, or simply by ignoringthe teratoma component and referring only to its malignant component: embryonalcarcinoma and/or choriocarcinoma.


Location
Despite their name, germ cell tumorsoccur both within and outside theovaryandtestis.
Infemales, germ cell tumors account for 30% of ovarian tumors, but only 1 to 3% ofovarian cancersinNorth America. Inyounger women germ cell tumors are more common, thus in patients under the ageof 21, 60% of ovarian tumors are of the germ cell type, and up to one-third aremalignant. Inmales, germ cell tumors of the testis occur typically after puberty and are malignant (testicular cancer). Inneonates, infants, andchildrenyounger than 4 years, the majority of germ cell tumors aresacrococcygealteratomas.
Males withKlinefelter'ssyndromehave a 50 times greater risk of germcell tumors (GSTs).In these persons, GSTs usually contain nonseminomatouselements, present at an earlier age, and seldom are gonadal in location.

Prognosis

The 1997 International Germ CellConsensus Classification is a tool for estimating the risk of relapse aftertreatment of malignant germ cell tumor.
A small study of ovarian tumors ingirlsreports a correlation betweencysticandbenign tumors and, conversely, solid and malignant tumors. Because the cysticextent of a tumor can be estimated by ultrasound, MRI, or CT scan beforesurgery, this permits selection of the most appropriate surgical plan tominimize risk of spillage of a malignant tumor.