Clear cell ovarian carcinoma

Clear cell carcinoma of the ovary is a subtype of malignant ovarian epithelial tumor.

Epidemiology

They represent ~2-5% of all ovarian carcinomas and ~4-12% of epithelial ovarian neoplasms. The mean age at presentation is ~10 years younger than for other ovarian epithelial tumors (peak ~55 years ⁶).

Associations

Clear cell carcinoma may develop in patients with endometriosis (~25% of cases) who develop ovarian cancer. This may be to an ARID1A gene mutation ⁴.

Pathology

Clear cell tumors are thought to arise from the embryonic mesonephros. Macroscopically, appearances are of a large unilocular cystic mass with protruding solid nodules. These are histologically very similar to clear cell carcinomas of the endometrium, cervix, or vagina. 

Radiographic features

Common imaging findings in clear cell carcinoma include a unilocular or large cyst with one or more solid nodular protrusions into the cavity.

CT

Typically seen as a large unilocular, mainly cystic, smooth marginated mass with lumen-protruding solid components and high-attenuating cystic components ⁵.

MRI

Often seen as a cystic ovarian mass with the margin being generally smooth. Solid protrusions are often both round and few in number.

Signal characteristics include:

• T1: can vary from low to very high (often dependent on hemorrhagic components, not a specific feature)

Treatment and prognosis

Staging is the same as general ovarian cancer staging.

They are almost always malignant although the majority (75%) of clear cell carcinomas present as stage I disease whose prognosis appears to be better than that of other ovarian cancers of comparable stage. Overall response to chemotherapy in advanced stages is considered poor ³.

See also

• ovarian tumors