Adnexal Masses Part II: Epithelial Neoplasms
/On today’s episode, we start into epithelial neoplasms of the ovary, which comprise about 90% of cancers of the ovary, fallopian tube, and peritoneum. Here are the show notes in outline format!
Benign epithelial neoplasms
Serous cystadenoma
Among the most common benign ovarian neoplasms (20-25%); sized 5-20 cm
Benign, but if persistently symptomatic, can have surgical removal
There is no good data regarding the decision to observe or remove if they are asymptomatic, but decision to operate may be guided by age, size of mass, ultrasound appearance, family history or other risk factors for ovarian cancer + medical comorbidities
Mucinous cystadenoma, lining similar to viscera or gastric lining
<5% of ovarian neoplasms
Contains mucin
Treatment same as above
Borderline ovarian epithelial neoplasms
Serous borderline neoplasms - most common histologic subtype of borderline tumors and accounts for 65% of all borderline ovarian neoplasms
Usually confined to the ovary and is slow growing
10 year survival rate is 95-100%, though late recurrences are not uncommon
Prognosis is still excellent even if there is presence of peritoneal implants and regional lymph node involvement
Histology: serous epithelial proliferation; more complex architectural patterns than a serous cystadenoma, and can have areas of microinvasion (area of cells <5 mm that are invading into the stromal core of the papillae or cyst wall); if it’s >5 mm, then it should be classified as a low-grade serous carcinoma
In fact, serous borderline neoplasms have similar immunophenotype and molecular biology to LGSC and may suggest that LGSC can arise from borderline neoplasms
Treatment: surgery
Mucinous borderline neoplasm - nearly always confined to ovary, unlike serous
Usually appears large, unilateral, multilocular cyst with smooth, white capsule
Epithelial lining with two general types: GI type and endocervical (or seromucinous) type
Approximately 10-20% exhibit microinvasion
Treatment: surgery
Endometrioid borderline neoplasm - biologic potential between cystadenomas/adneofibromas and invasive endometrioid adenocarcinoma of the ovary
Uncommon - 2-10% of borderline neoplasms
General appearance: firm, with smooth surface and multiple small cysts with clear or hemorrhagic fluid
Histologically, have adenofibromatous pattern with nodular architecture, but more proliferative with appearance similar to complex atypical hyperplasia of the endometrium
Actually same criteria exist to differentiate it from invasive carcinoma as there is between complex atypical hyperplasia and well-differentiated endometrioid adenocarcinoma of the endometrium
Microinvasion can be seen
Carcinomas
We will talk about staging and treatment in another episode!
High-grade serous carcinoma (70-80% epithelial carcinomas)
Most common type of ovarian cancer, and accounts for 70-80% of all malignant ovarian neoplasms
Peak age range is 45-65 years; usually diagnosed at advanced stage
Histologically, HGSC will infiltrate and destroy
BRCA1 or BRCA2 germline mutations are found in up to 10% of women with HGSC
Women with these mutations have a 30-50% risk of developing ovarian carcinoma by age 70
Low-grade serous carcinoma (<5%)
Uncommon
Typically diagnosed at advanced stage; therefore, long-term prognosis is poor
Slow-growing, indolent tumors with relative insensitivity to platinum-based chemo
Can be found alongside noninvasive serous borderline tumors
LGSC differentiated from HGSC by cytologic features; usually have more uniform nuclei, lower mitotic activity; also has numerous psammoma bodies
Endometrioid carcinoma (10%)
Unlike serous carcinomas, it is usually identified at an early stage, and therefore, patients have a better prognosis
Tend to be relatively chemosensitive
Thought to arise from endometriosis and is associated with carcinoma of the endometrium in 15-20% of cases
Histologically, this type of carcinoma resembles the uterine counterparts
Clear cell carcinoma (10%)
Present most commonly in perimenopausal women in 40s or 50s
Often presents at an early stage, relatively good prognosis due to absence of distant metastases
However, if it is present at advanced stage, it has worse prognosis than serous or endometrioid carcinoma, because it is not as sensitive to platinum-based chemo
Possibly arises from endometriosis
Mucinous carcinoma (3%)
Nearly all present in early stages, usually stage I; often seen with borderline neoplasm
Reason it’s found early is because it is usually large upon discovery: 8-20 cm, but can be even larger
Tends to be cystic or solid, unilateral, and confined to the ovary
There are two patterns of “invasion” - infiltrative invasion and expansile growth pattern
Infiltrative: obvious destructive stromal invasion - worse prognosis
Expansile growth pattern: does not demonstrate obvious stromal invasion, but has complex architecture; better prognosis