Ans. is 'a' i.e., DysgerminomaOvarian mass in 25 year old female suggests the diagnosis.Although dysgerminomas are relatively uncommon among all ovarian neoplasms (only accounting for only about 2%) they account for about 32.8% of malignant ovarian germ cell neoplasms.Majority of cases arise in adolescent and young adults in whom they account for one third of all ovarian neoplasm.The growth of dysgerminomas is usually rapid as a result patients often presents with abdominal enlargement and pain due to rupture with hemoperitoneum or torsion.Tumour markers associated with dysgerminoma.Dysgerminomas can contain syncytiotrophoblastic giant cells that produce placental alkaline phosphatase and lactate dehydrogenase.Alpha fetoproteinIn general dysgerminomas do not produce alpha fetoprotein (AFP) although borderline elevation are described. hCGhCG is associated with only 3.5% of dysgerminomas.Endodermal sinus (Yolk sac Tumour)Endodermal sinus tumour also called yolk sac tumour makes upi4-20% of all malignant ovarian germ cell neoplasms.These neoplasms usually occur in young girl and women.The median age of presentation is 23 years and one third of patients are premenarchal.Histologically they are associated with schiller duval bodies.Patients with endodermal sinus tumour often presents with abdominal pain and pelvic mass, similar to dysgerminomas - Turnover growth can be very rapid and aggressive.Serum AFP levels are elevated in a significant number of patients.Malignant teratomaImmature teratoma are also called malignant teratomas.They comprise less than l% of ovarian teratomas and are most common in first two decades of life.These neoplasms are typically composed of tissue from three germ layers i.e., ectoderm, mesoderm, endoderm arranged in haphazard manner.The clinical presentation is similar to that of other ovarian germ cell neoplasms (incidentally discovered adrenal mass abdominal enlargement of pain).AFP or LDH are elevated in some cases.Serous mucinous cystadenomaSerous and mucinous cystadenomas are among the most common benign ovarian neoplasm.Cystadenomas will not present as solid mass on ultrasound. It would be a cystic mass.They are thin walled, uni-or multiocular and range in size from 5 to over 20 cm.Ovarian epithelial tumours usually present with elevation in CA-125.Markers secreted by germ cell and sex cord-stromal tumors of the ovary AFPhCGLDHE2InhibinTestostAndroDHEAGerm cell tumors Dysgerminoma-+-++-----Embryonal+-++-+-----Immature teratoma+--+-+----+-Choriocarcinoma-++------Endodermal sinus+-+--- -Gonadoblastoma---+-+-+-+-+-Polyembryoma+-+------Mixed germ cell+-+-+------Sex cord-stromal tumors Thecoma-fibroma--------Granulosa cell---+-++- -Sertoli-Leydig+---+-+-+-+-+-AFP: alpha-fetoprotein hCG: human chorionic gonadotrophinLDH: lactate dehydrogenaseE2: estradiolTestost: testosteroneAndro: androstenedioneDHEA: dihydroepiandrostenedione