Images by Carinelli, EIO.

Borderline ovarian tumors

Definition

Borderline ovarian tumors

(BOTs) are epithelial tumors

with a low grade of

malignancy.

They are defined as epithelial

tumors with a stratification of

the epithelial lining, but with a

lack of frank stromal invasion.

Consequently they show low

potential to invade or

metastasise.

BOTs account for 10–15 % of epithelial ovarian tumors.

The incidence of BOTs is estimated to be 4.8/100 000

women per year.

These tumors occur in younger women, with almost 30% of

patients younger than 40 years, and they are often

diagnosed in an earlier stage of the disease than invasive

carcinomas.

About 80% of women with BOT present with stage I

disease.

More than 95% of BOTs are either of serous or mucinous

histotype. Other rare types are endometrioid, clear cell, and

Brenner tumors.

Borderline ovarian tumors

Incidence

BOTs seem to arise from cortical inclusion cysts of the

ovarian epithelium, that are exposed to metaplastic and

dysplastic transformation into BOT.

Mutations in BRAF and KRAS characterise the non-

invasive serous tumours and invasive low grade serous

carcinoma and mutations in both genes occur early in

tumour progression.

PrognosisWhen the disease is diagnosed at stage I, prognosis is

excellent and fertility-sparing conservative treatments

for BOT should be offered to young women.

Therefore accurate preoperative diagnosis is of utmost

importance for planning appropriate management.

Borderline ovarian tumors

Pathogenesis

In some cases BOTs can be associated with extra

ovarian disease, defined as ‘implants’ rather than

metastases. The prognosis in these cases in worse.

These implants are

further sub-classified as

invasive or non-

invasive, and require

different treatment.

Image by Franchi D, Mancari R - EIO

Borderline ovarian tumors

Prognosis (2)

Serous borderline tumors (sBOT)

sBOT form bilateral (30–40%) large cystic and/or solid masses

with papillary epithelial structures. The inner layer of the cyst is

composed of confluent papillae of different dimensions.

Mucinous borderline tumors (mBOT)

mBOT have been subclassified into two clinico-pathologic

forms: gastrointestinal-type and endocervical-like tumors.

Gastrointestinal type tumours account for 85–90% of mBOTs

and they have similar histologic features to primary mucinous

carcinomas of the appendix, appearing mainly as cystic

masses.

Endocervical-like tumours show a morphology similar to serous

borderline tumours.

Borderline ovarian tumors

Prognosis (2)

Image by Franchi D - EIO

Borderline ovarian tumors

Serous borderline ovarian tumor with

evidence of disease on the ovarian

surfaceImage by Franchi- EIO

Borderline ovarian tumors

sBOT

sBOTs and endocervical-type mBOTs have similar sonographic

features. Compared with the intestinal-type mBOTs, these tumors

are characterised by a smaller maximum diameter, fewer locules

(they are usually unilocular-solid lesions) with a positive ovarian

crescent sign, a higher number of papillary excrescences within

the lesions and a higher rate of vessels inside the papillations.

Solid morphology is very rare in both groups of lesion.

Intestinal-type mBOTs are usually unilateral, large, multilocular

tumors with a smooth capsule and no clear definition of solid tissue

or papillary projection. A multilocular nodule arising from the inner

cyst wall (‘honeycomb nodule’) can be detected.

Borderline ovarian tumors

Ultrasound characteristics

Unilocular-solid cysts or multilocular-solid cysts

Multiple papillary projections

with irregular surface

Ovarian Crescent sign

Image by Franchi - EIO

Borderline ovarian tumorsMorphological features suggestive of

serous type or endocervical type BOT

Image by Franchi - EIO

Borderline ovarian tumorsUltrasound characteristics: typical

appearance

Image by Franchi - EIO

Borderline ovarian tumors

sBOTS

Clip by Franchi EIO

Borderline ovarian tumors

sBOTS

Images by Franchi EIO

Borderline ovarian tumor with extra

ovarian disease

Borderline ovarian tumors

sBOTS

• Multilocular Cysts in 55% of cases

• > 10 locules in 80% of cases

• Honeycomb nodule present in 50% of cases

• Thick echogenic fluid content

Image by Franchi - EIO

Borderline ovarian tumorsMorphological features suggestive of

intestinal type borderline tumor

Honeycomb nodule

Images by Franchi EIO

Borderline ovarian tumors

mBOTS

Clip by Franchi - EIO

Borderline ovarian tumors

mBOTS

The symptoms of BOTs may be absent and the

diagnosis can be infrequent when the lesion

has a small diameter. This occurence is more

frequent with endocervical-type mBOTs and

sBOTs.

Symptoms are related to the presence of an

abdominal or pelvic mass with huge

dimensions, with bloating and pain being the

usual presentation.

Borderline ovarian tumors

Clinical symptoms

Due to the younger age of presentation of BOTs, a

correct preoperative diagnosis is of the utmost

importance in the management of these patients, who

may benefit from conservative treatment .

In these cases, ultrasound allows careful follow up of

the patient, as it is able to detect very small

recurrences within normal ovarian parenchyma. This

makes it possible to perform repeated fertility sparing

surgery.

Borderline ovarian tumors

Conclusion