Ovarian Dysgerminomas Workup

Tests for pregnancy and sexually transmitted diseases

One should always initially obtain a pregnancy test. This test should be mandatory in any woman of reproductive age, even at the extremes of reproductive age, who presents with abdominopelvic symptoms.

Because dysgerminomas affect women of reproductive and sexually active age, cultures for gonorrhea and chlamydial infection and a wet mount are recommended at the time of speculum examination, especially if patients experience abdominopelvic pain and/or fevers. In this way, sexually transmissible diseases may be detected and treated before surgery.

Once a pelvic mass is detected, especially in younger female patients, the standard workup for suspected germ cell tumors (GCTs) requires lactate dehydrogenase (LDH), alpha-fetoprotein (AFP), and beta-human chorionic gonadotropin (beta-hCG) levels. If any levels are elevated, they may assist in the diagnosis and/or follow-up of women with malignant ovarian GCTs.

Other laboratory studies

Dysgerminomas have most commonly been associated with elevations in LDH, although it is not elevated in all cases. Occasionally, dysgerminomas may become infiltrated with syncytiotrophoblastic giant cells, which produce beta-hCG. Elevations in AFP are even less common. However, preoperative evaluation of all of these markers is suggested in patients with suspected ovarian GCTs/dysgerminomas. Additionally, serum inhibin levels can be useful in this age group. Although inhibin B seems to be more sensitive and has a greater elevation in GCTs, inhibin A can also be elevated with inhibin B or, more rarely, without elevation of inhibin B, as sex cord stromal tumors are also in the differential for women in this age group who present with pelvic masses.

Therefore, useful tumor markers for the workup of dysgerminomas include the following:

• Beta-hCG

• AFP

• LDH

• Inhibin A and B

• Cancer antigen 125 (CA-125) - For epithelial tumors

Nuclear protein in the testis

A potentially useful test for ovarian GCTs, including dysgerminomas, is immunoreactivity of nuclear protein in the testis (NUT). In situ and invasive germ elements of dysgerminoma associated with gonadoblastoma were positive for NUT in a study that evaluated NUT immunostaining in mature cystic teratomas and malignant ovarian GCTs. ^[2]

Imaging should never replace a careful history and physical examination in evaluating a patient with an ovarian mass. The initial approach should be an attempt to determine the nature and extent of the mass.

Transvaginal ultrasound is a good preliminary imaging modality to determine if the mass is ovarian and, more importantly, if it has any malignant features (eg, thickened septations, solid and cystic components). Free abdominal fluid and bilateral masses heighten the suspicion of malignancy. Occasionally, pelvic magnetic resonance imaging may be necessary to better assess anatomy if a nonovarian origin for the mass is suspected. Computed tomography (CT) scanning of the chest, abdomen, and pelvis is frequently used to evaluate for metastasis.

Occasionally, patients may present with signs or symptoms of gastrointestinal or genitourinary obstruction. In these cases, additional studies to consider in the workup include the following:

• Barium enema

• Upper gastrointestinal series

• Colonoscopy

• Intravenous pyelography (IVP) - No longer used if CT scanning is used

Diagnosis of malignant ovarian tumors must be made surgically through either laparoscopy or laparotomy. The appropriate surgical approach depends on findings from the clinical examination, imaging, and laboratory workup, as well as an index of suspicion for a malignancy. Care should be taken not to rupture ovarian masses that are suggestive of malignancy. If laparoscopy is undertaken and cyst drainage or morcellation is to be performed, the mass should be placed into a laparoscopic bag to avoid tumor spillage or dissemination. Dysgerminomas, like all ovarian cancers, are staged surgically.

Grossly, dysgerminomas have a solid texture, with a tan, fleshlike appearance. Microscopically, dysgerminoma cells are round and ovoid and contain an abundance of clear cytoplasm secondary to glycogen buildup. The nuclei are irregularly shaped and contain more than one prominent nucleolus. These cells tend to coalesce, forming cords and sheets that are identified easily through low-power magnification. Granulocytic and lymphocytic infiltration within the intervening fibrous stroma and granulomatous changes also can be observed. Interestingly, cystic teratomas occasionally have small nests of dysgerminomatous tissue and vice versa. Additional assays that detect transcription factors GATA-4, Ihh (Indian hedgehog), and BMP-2 (bone morphogenic protein 2) may also prove useful in differentiating between dysgerminoma and other germ cell tumors.

Note the image below.

Ovarian dysgerminomas. Microscopic image at 20 X.

International Federation of Gynecology and Obstetrics (FIGO) staging 2014

Stage I (as follows) - Limited to ovaries:

• Ia - Limited to one ovary, capsule intact, negative washings, and no ovarian surface implants

• Ib - Limited to both ovaries, negative washings, and no ovarian surface implants

• Ic - Ascites with malignant cells on peritoneal washings or extension beyond the capsule in either Ia or Ib

  • Ic1 - Surgical spill

  • Ic2 - Capsule rupture before surgery or tumor on ovarian surface

  • Ic3 - Malignant cells in the ascites or peritoneal washings

Stage II (as follows) - Pelvic extension:

• IIa - Involvement of uterus or fallopian tubes

• IIb - Extension to the bladder or rectum

Stage III (as follows) - Peritoneal implants outside of pelvis or positive lymph nodes:

• IIIa1 - Positive retroperitoneal lymph nodes

  • IIIa1(i) - Metastasis  ≤10 mm

  • IIIa1(ii) - Metastasis >10 mm

• IIIa2 - Microscopic seeding of abdominal surfaces, implants < 2 mm ± positive retroperitoneal nodes

• IIIb - Abdominal peritoneal implants ≤2 cm ± positive retroperitoneal nodes - Includes extension to capsule of liver or spleen

• IIIc - Abdominal implants >2 cm ± positive retroperitoneal nodes - Includes extension to capsule of liver or spleen

Stage IV (as follows) - Distant metastases:

• IVa - Pleural effusions - Must confirm with positive cytology to be deemed stage IV

• Hepatic and/or splenic parenchymal metastases and/or metastases outside of the peritoneal cavity (including positive inguinal or other extra-abdominal lymph nodes)

• See additional notes under Surgical Care.