Ovarian cysts Flashcards
in post-menopausal women when is a cyst size considered significant and should be reported on imaging?
a cyst >= 1cm should be reported anything below this level is considered insignificant and does not need reporting
Describe how the RMI is calculated
RMI = risk of malignancy index
RMI = U * M * Ca-125
U= USS score ( 1 feature = 1 score, 2 or more features = 3 points )
M = menopausal status ( pre-menopausal = 1, post menopausal = 3 points)
Ca-125 = level of serum CA-125 level
list the USS features that are used to calculate the RMI score
USS features:
1. ascites
2. metastases
3. bilateral
4. multilobulated
5. solid areas
what is the RMI level governed by NICE that suggest high risk of ovarian cancer?
> 250
what is the RMI level governed by RCOG that suggests high risk of malignancy?
> 200
what is the sensitivity and specificity of RMI at 200
78% sensitivity and 87% specificity
what is the sensitivity and specificity of RMI at 250
sensitivity = 70% and specificity = 90%
CA-125 considered a highly sensitive and specific test? True or false
false - sensitivity and specificity is only 78% (is only raised in epithelial ovarian cancers)
what is CA-125
CA-125 is a tumour marker used for epithelial ovarian cancers.
It is an antigen that is derived from epithelial and coelomic and mullerian epithelium
what other conditions can raise Ca-125
any condition that irritates the peritoneal lining e.g. TB, ascites, hepatitis, cirrhosis, pancreatitis
peritoneal primary cancers
cancers including lung/ breast and colon cancers
endometriosis, fibroids, PID, acute ovarian torsion or haemorrhage
what can cause decreased levels of CA-125
caffeine, hysterectomy, smoking
what is the pooled sensitivity and specificity of CA-125 in differentiating benign from malignant tumours in PMW
78% (this is considered low)
in post-menopausal women presenting with an ovarian cyst what tumour markers should be measured?
just Ca-125 (no evidence to check LDH, AFP and HCG - these are for germ cell tumours in women <40 years)
describe the IOTA benign rules
benign (b) rules are 5 in total:-
1. acoustic shadowing
2. no blood supply
3. unilocular cyst of any size
4. multilocular cyst < 100mm
5. if a solid mass is present <7mm
describe the IOTA malignant rules
5 in total:
1. irregular, multilocular cyst > 100mm
2. solid component >7mm
3. at least 4 papillary structures
4. good blood flow
5. ascites
what are the majority of cysts in pre-menopausal women (benign or malignant)
benign
what does the risk of malignancy cyst increase to as age increases?
1 in 1000 aged 30 to 3 in 1000 aged 50
describe the appearance of a follicular cyst
often unilateral
must be >3cm to be called a cyst, can reach 8-10cm
lined with granulose and theca cells
what factors increase the risk of follicular cysts developing
linked with more ovulations
- ovulatory induction e.g. tamoxifen
- early menarche/ late menopause
-nuliparity
- GNRH analogues
USS imaging describes a unilateral cyst that is thicked wall with a ring of vascularity surrounding the cyst
what type of cyst is being described?
1. follicular cyst
2. granulose cell cyst
3. dermoid cyst
4. corpus luteal cyst
4- corpus luteal cyst (with its characteristic ring of fire surrounding it)
a 35 year old lady has an USS scan due to experiencing cyclical pelvic pain. The USS describes multiple thick walled homogenous cysts with a ground glass appearance. there is no solid component to the cysts.
what type of cysts are being described?
A- FOLLICULAR CYST
B- DERMOID CYST
C- ENDOMETRIOMAS
D- YOLK SAC CYST
c - Endometriomas
what is the most common type of cyst that develops in molar pregnancy
theca lutein cyst
what are the difference between serous cystadenomas and mutinous cystadenomas
serous cystadenomas are usually unilocular, can be bilateral in up to 30% of cases
mucous cystadenomas are usually multi-locular, unilateral and grow extremely large
what type of epithelium is found in a brenner tumour
transitional epithelium
USS demonstrates a yellow-grey and white solid tumour . Histology demonstrates the presence of transitional epithelium.
What type of cyst does this demonstrate?
A- FOLLICULAR CYST
B- MATURE TERATOMA (DERMOID CYST)
C- GERM CELL TUMOUR
D- BRENNER TUMOUR
Brenner tumour
what is the most common type of germ cell tumour
mature teratoma (dermoid cyst)
describe the appearance of a mature teratoma (dermoid cyst)
This is often a benign cyst
- can consist of all three embryological layers e.g. ectoderm, mesoderm and endoderm
- USS appearance - calcification can be visible, fluid level, distal acoustic shadowing, distinct nodule called Rokitansky nodule (represents hair in fluid)
what age group do mature teratomas (dermoid cysts) often present in?
what is a concern with their presence?
reproductive age group, high risk of torsion
what is the most common type of malignant germ cell tumour?
A- MATURE TERATOMA (DERMOID CYST)
B -DYSGERMINOMA
C-IMMATURE TERATOMA
D- ENDODERMAL SINUS TYMOURS
b - dysgerminoma (this is an undifferentiated type of GCT)
how can germ cell tumours be classified
differentiated and undifferentiated
- most of GCT are differentiated
- dysgerminoma is undifferentiated
what blood tests should be done to rule out a GCT
hCG, alpha fetaprotein, LDH (note LDH recommended in US guidelines but not UK)
name the types of differentiated GCT
- mature teratoma (dermoid cyst) - most common benign GCT
- endodermal sinus tumours (previously called yolk sac tumour)
- choriocarcinoma
- immature teratoma
USS scan describes a vary large, vascular lobulated adnexal mass with irregular internal echogenicity.
The patient is 20 years old. bloods demonstrate raised hCG and LDH.
Histology demonstrates sheets of nests uniform cells with clear or eosinophilic cytoplasm and distinct cell membranes
what type of cyst is being described?
dysgerminoma
