serous cystadenocarcinoma of the ovary

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Ovarian serous cystadenocarcinoma is the malignant form of ovarian serous tumor, the most common type of ovarian epithelial tumor. It is the most common type of ovarian malignancy.

Increasingly, high-grade serous carcinoma and low-grade serous carcinoma are recognized as distinct tumor types rather than a spectrum of disease grade as implied by the nomenclature (see Pathology for more).

Terminology

Serous ovarian tumors are traditionally described with a "cyst-" prefix because of their primarily cystic composition, e.g. cystadenoma, cystadenocarcinoma.

Epidemiology

Account for the largest proportion of malignant ovarian tumors , representing over 50-80% of all malignant epithelial ovarian tumors . Serous ovarian cystadenocarcinomas account for ~25% of serous tumors.

The incidence peaks around the 6 to 7 decades of life .

Pathology

Macroscopic appearance

multilocular cystic ovarian tumor with papillary projections

Microscopic appearance

classified as high-grade versus low-grade carcinoma :
- high-grade serous carcinoma (HGSC)
  - common (70-80%)
  - thought to originate from distal fallopian tube epithelium
  - high grade nuclear features (e.g. nuclear pleomorphism, abnormal mitotic figures)
  - characterized by intratumoral heterogeneity
  - nearly ubiquitous p53 positivity
- low-grade serous carcinoma (LGSC)
  - uncommon (~5%)
  - thought to mostly represent malignant degeneration of serous cystadenoma
psammomatous bodies may be present in either LGSC or HGSC, but more numerous in LGSC

Risk factors

Recognized risk factors include:

nulliparity
early menarche
late menopause
positive family history
infertility

Markers

elevated serum CA-125 (>90% of cases )

Staging

See ovarian cancer staging.

Radiographic features

Imaging plays an important role in the diagnosis of ovarian tumors and in the assessment for metastatic disease. However, surgical evaluation is the standard of care for staging of disease.

Typical imaging features of ovarian cystadenocarcinoma include:

cystic adnexal mass with a substantial solid component
calcification uncommon, but can be seen (~12%)
- also seen in serous cystadenoma and other tumors
frequently bilateral

In the setting of suspected ovarian cystadenocarcinoma, features suggestive of extra-ovarian metastasis include:

ascites - often of disproportionately large volume
peritoneal nodularity
lymphadenopathy

Ultrasound

mixed cystic/solid lesion
- more heterogeneous than a serous cystadenoma
- papillary projections, thick septations, and/or solid components
ascites
- concerning for peritoneal metastatic spread
- discrete peritoneal deposits may be seen
color Doppler is useful to confirm vascularity of the solid components
- quantitative parameters (resistive index (RI) and pulsatility index (PI)) do not reliably predict malignancy

CT

CT may be used for preoperative evaluation to assess for metastatic disease, e.g. peritoneal nodularity, ascites, or intrathoracic lesions.

MRI

MRI provides the most detailed imaging evaluation for ovarian malignancies and may be used in either preoperative evaluation or post-treatment follow up.

T1
- cystic portions are T1 dark unless there has been intralesional hemorrhage (keep in mind mucinous tumors also have brighter T1 appearance in the cystic component)
- solid portions are T1 intermediate
T2
- cystic portions are T2 bright
- solid portions are T2 intermediate
T1 C+: solid portions enhance
DWI/ADC
- solid components restrict diffusion
- metastases may exhibit restricted diffusion. The cystic components are high T2, low T1 signal unless there has been intralesional hemorrhage (c.f. , where there is typically slightly increased T1 signal of the cystic component).