Ultrasound Evaluation of Pediatric Gynecologic Emergencies

Introduction

Hi, I'm Dorothy Ulli.

I'll be discussing pediatric gynecological emergencies evaluation with ultrasound.

Today we'll review techniques of ultrasound evaluation of pediatric gynecological emergencies.

We'll view differential of pelvic pain at various stages of pediatric life

and we'll discuss the appropriate radiologic workup of the emergencies of the pediatric GYN exam.

Appropriate Imaging and Interpretation

Appropriate imaging

and correct interpretation of gynecological emergencies

requires the knowledge of what is normal

and what the differential diagnosis is.

At various stages of pediatric life,

we'll discuss the uterine

and vaginal congenital abnormalities

and tumors as well as adnexal abnormalities, including

tumors, torsion and pelvic inflammatory disease.

Ultrasound Techniques

Ultrasound is the predominant imaging for girls

with pelvic pain or masses.

We can use five to nine megahertz transducers for infants

and three to five megahertz transducers.

For children and the adolescent, it's important

to perform the exam with a filled bladder

with young infants.

Proper timing and a flexible schedule allows

to successfully examine the pelvis without having

to catheterize the bladder.

At times, water enemas can be useful

to rule out pseudo masses or to search for the uterus.

The trans labial approach could be useful for looking

for vaginal outflow obstruction.

Transvaginal exams can be used

for sexually active teenagers, rule out ectopic pregnancies

and tubo ovarian abscesses.

Doppler should be used to assess the vascular nature

of tumors and can be extremely helpful in looking

for ectopic pregnancies

and maybe if some use in assessing for ovarian torsion.

While this is a talk on ultrasound, sometimes CT

or MRI can be useful in looking for areas obscured

by overlying air.

With CT, we can assess for calcifications fat

and gives us a large field of view for large masses.

MRI is particularly helpful for uterine anomalies.

Looking at multiplanar imaging

and perfusion characteristics with children, of course

the drawbacks are cost, the need for sedation

and radiation exposure with ct.

The Uterus

Let's start with the uterus.

In the newborn period you have a uterus that looks

slightly pubertal and contour.

Because of maternal hormonal stimulation, it may measure

as much as four to four and a half centimeters in length.

This quickly decreases in size

and becomes spade like in configuration.

With the fundus the same or smaller in size than the cervix.

By three to eight years of age,

the uterus starts growing slowly in size,

but typically you do not see an endometrial stripe.

As the girl hits puberty,

there's a rapid enlargement of the uterus.

The fundus grows much larger than the cervix

and descends deeper into the pelvis with a visible

endometrial canal.

So whenever we look at the uterus in a child, it's important

to decide whether it's pre pubertal

or pubertal in configuration.

So here is an 18-year-old with a very small

uterus in which the cervix and uterus are similar in size.

Following therapy, there's been an increase in the uterine

thickness as compared to the cervix.

There's not much to actually see in the vagina.

It's hypo echogenic and tubular

and looks fairly flat in the transverse plane.

It should be relatively empty. In young infants.

You may have anal atresia with a rectovaginal fistula

and you may see some echogenic material filling

the vaginal canal.

In this scenario,

when we look at the embryogenesis of the Malian ducts,

there are two that are formed

and they form the fallopian tubes, uterus, cervix,

and the upper two thirds of the vagina.

The ovaries come from the germ cells

of the primitive yolk sac while the lower third

of the vagina is separate embryologic origin from the

SVA bulb, you can have

complete agenesis of mullerian ducts

and that can result with complete absence of the uterus

and they're often associated with bladder

and kidney abnormalities.

Here we have an ectopic kidney.

You can have failure of formation of one

of the horns and this results in a unicornuate uterus.

If a rudimentary horn is present, it may be obstructed

and present as a pelvic mass

with Mr CT or VC Gs.

You can help assess the rudimentary horn.

Here we have a fluid-filled vaginal

obstructed vaginal canal that's compressing the other side

of the vagina

and again associated with a single kidney in absent kidney

on the right and one kidney on the left.

When there is failure of lateral fusion,

you may have a spectrum of abnormalities.

You can have two vaginal canals

and didelphys with two separate horns.

You can have a bicornuate uterus

with a single vaginal canal and two endometrial

or you can have a septated uterus.

Ultrasound can help differentiate between the two.

Here we have didelphys with two separate horns.

MRI and cystogram can help

to separate whether there's a single vaginal canal

or two vaginal canals.

As we see here,

when there is failure of vertical fusion,

there's a separation between the upper two thirds

of the vagina and the lower one third of the SVA bulb.

This can result in hydro or hematocolpos.

Approximately two thirds of these are due

to an imperforate hymen with one third due

to complete vaginal membrane.

So metro means uterus.

Colpos is the vagina

and it can be distended by fluid hydro

or echogenic blood hemato

and the neonate, the mass looks fairly solid

and it will dilate the vagina and less so the uterus.

When one encounters a mass at the level of the bladder,

it's important to look at the superior aspect of the mass

and that's where you'll be able

to identify the less distended uterus.

In menarche, you may have a girl who's been complaining

of intermittent pain

and has had amenorrhea By ultrasound,

you again can see the vagina filled with blood

as well as the uterus.

It's important to look very carefully at the superior aspect

of the mass because at times the uterus is not distended at

all and is a little nubbin at the superior aspect.

But this helps to confirm the diagnosis

at times by ultrasound,

the findings may be somewhat confusing.

Here again, we see an echogenic mass posterior

to the bladder with some echogenic tubular structures which

turn out to be blood filled fallopian tubes.

Here again on the longitudinal image it's important

to look carefully for where the uterus resides on top

of the blood filled vaginal canal.

MRI times can be helpful for more complex cases

of vaginal atresia

and we can actually identify vaginal atresia as early

as in the prenatal life.

Here we have a fluid filled structure

with the cervix sitted on top of this infant who had

a hematocolpos from vaginal atresia.

Rarely we can actually have invagination of the uterus.

This actually looks like an intussusception

and indeed this was uterine inversion

from a teratoma as a lead point.

Uterine and Vaginal Tumors

Luckily uterine

and vaginal tumors are fairly rare in pediatrics.

Unfortunately, when present they're typically malignant,

they may present with pain mass vaginal discharge,

they can actually protrude from the introitus by ultrasound.

They may look like a polypoid mass

actually growing into the bladder MRI at this time can be

very helpful in looking at the extent

with this larger field of view.

Endodermal sinus tumors typically present in infants

between eight and 15 months of age.

Clear cell adenocarcinomas typically present after menarche.

The most common is sarcoma botryoides.

These typically present in children less than three years

of age and they originate from the urogenital sinus remnant

by ultrasound sarcoma botryoides classically are called the cluster

of grapes where you see multiple cysts

with some solid components.

As mentioned, they can grow into the bladder

and cause unusual bladder thickening as well

as grow into the labia and urethra.

Here's a 2-year-old with a sarcoma botryoides mimicking

a hematocolpos.

The key here is the age of the patient.

Remember with hematocolpos

you should see either a mass in the newborn

period or at menarche.

So the two years of age was more consistent

with a rhabdomyosarcoma.

The Ovary

Let's move on to the ovary.

You should be able to identify the pediatric ovary up to 65%

of newborns and after the age of two and up to 80% of cases.

Remember that it can be all along the embryologic course,

so it can be as low down as the labia

or as high up as the inferior border of the kidney.

Post puberty, the ovary tends to be lower in the pelvis,

but in younger children the ovary tends

to be higher up than expected.

At the posterolateral fold of the broad ligament

size changes again, early on it's fairly large due

to maternal hormones.

It'll decrease in size

and then start increasing when puberty develops.

As it increases at puberty, it can become as large

as 18 centimeters cubed.

Typically physiologic cyst will be seen

and are related to follicular maturation.

In adolescents you may see unstimulated follicles

and pre ovulatory follicles

that measure less than three centimeters

and these can be normal if

it measures greater than three centimeters.

We will call this a true ovarian cyst

and this can be seen prenatally in infancy

as well as late childhood.

If they're large and cause pain.

The patient may present with mass fever, irritability,

they may tort on themselves or bleed or even rupture

and all of these can result in the pain the patient's

feeling by ultrasound.

We look for a thin walled cystic structure measuring greater

than three centimeters.

Remember that ovarian masses in young infants

and young girls often present as an abdominal mass

as the pelvis is quite small.

Any ovarian masses tend to move up into the abdomen

and can mimic many abdominal masses.

When we see these cysts measuring less than four

to five centimeters,

they typically involute in the neonatal period

and they may take up to three to four months to resolve,

but typically can be asymptomatic

if they measure greater than five centimeters.

However, there is a higher risk of torsion

and they may need to be drained.

Cysts can cause symptoms if they bleed

and they can simulate appendicitis.

This is typically a diagnosis of exclusion.

You may have the fishnet weave appearance, of a complex

cystic structure, but it's important to document resolution

as these may actually be cystic neoplasm.

So I have a question. What percentage

of pediatric ovarian tumors are malignant?

It turns out it's 35%.

The most common are the benign cystic teratomas

or cystadenomas

and the malignant 35% include germ cell stromal sex cord

and epithelial tumors.

So cystic teratomas are about 40 to 50%

of ovarian neoplasms in children

and they're typically benign.

They come from the three germ cell layers, the ectoderm,

mesoderm, and endoderm.

The majority present at greater than six years of age.

But remember that about 15% of these can be malignant.

They may have symptoms from

bleeding torsion rupture by x-ray.

You may see these strange calcifications in the pelvis

By ultrasound, they can be hyperechoic due to the fat hair

and sebaceous material.

They may have shadows

or they may simply be the tip of the iceberg with

no real way of truly measuring the size of the fatty mass.

By ultrasound When cystic, they're easy to easier

to identify and measure

and may have really no solid component associated with them.

Here we have an echogenic structure.

It's hard to know exactly how deep it goes into the pelvis

and this was a teratoma by ct.

CT or MR at times can be helpful in assessing the size

of the mass or calcification.

And remember that 10 per 20% of teratomas can be bilateral

as in this case whereby ultrasound we identified one

fatty teratoma and yet the other one was actually separate

and not a continuum of the same mass.

As mentioned, a third of ovarian tumors are malignant.

These are more commonly present post puberty

and often are hormonally

active by ultrasound.

They are complex

with thick septations papillary projections.

Typically they're not just cystic,

they'll have some soft tissue elements

and they have secondary ascites in peritoneal implants.

CT MR in these cases are useful for staging,

and getting a large field of view

as often these masses can be greater than 10 centimeters at

time of diagnosis.

The most common malignant OV neoplasm in children

is germ cell tumors.

Germ cell occur in 10%

of cases in epithelial carcinomas are fairly rare as well.

With granulosa thecal cell tumors, they may have estrogen

or androgen secretion.

Typically by ultrasound you'll see thick irregular

septations with solid components, they're fairly complex.

Sertoli leydig tumors typically have androgen secretions

and they more commonly have a solid presentation can also be

quite large and rarely have metastasis.

Ovarian Torsion

When we have a teenager with pelvic pain, one

of the differentials to consider is ovarian torsion.

If there's doppler demonstrated in the ovary,

does this exclude the diagnosis?

It's really not as simple as true or false.

One should always consider adnexal torsion in the

differential of a girl with acute or recurrent pelvic pain.

The diagnosis is important to make

as you can salvage the ovary,

but the symptoms unfortunately can be quite confusing.

With intermittent episodes with nausea, vomiting,

constipation, they may even have fever or pain.

Remember that with adnexal it may be partial or complete.

It may be secondary to an underlying mass in the ovary

or due to hydrosalpinx or a long meso ovarium

adnexal torsion presentation can be very nonspecific

and look different at different gestational ages.

In the young infant it may already be torted

with calcifications and debris levels acutely.

In a teenager it may simply be a swollen ovary

with multiple small follicles.

It also depends on the underlying mass,

whether it's a teratoma or a cystadenoma.

So here at puberty you may have simply a unilaterally

enlarged solid ovary with peripheral follicles.

And here we have a normal ovary on one side

and a large swollen adnexal ovary

with multiple small follicles.

Symptoms can be sudden or chronic.

With acute symptoms,

you may have a decrease in venous flow

with an elevated resistive index.

Chronically you may have a eventual decreased

flow in the arteries.

Finally, with arterial supply completely cut off,

you may have gangrene infection and peritonitis.

Unfortunately with doppler,

if you see flow in the central portion of the ovary,

that may help to rule out torsion.

But in normal ovaries flow may be difficult

to document essentially,

and there may be flow in partially twisted ovaries.

And if there's a cyst like a large teratoma,

you may not actually see flow in the cystic component.

So this limits the usefulness

of differentiating cystic lesions from torsion.

In girls with acute pain here in

a series by stark etal where they evaluated 14 torsions,

14 five had no flow, four had peripheral flow, three

actually had central flow.

And in this series by Krylon etal

with looking at 42 adnexal lesions,

there was no central flow in three torsions,

but also no flow in five cystic lesions without torsion

and there was external flow in two torsions.

Other Reasons for Pelvic Pain

Lastly, I'll just talk about the utility

of ultrasound In looking at other reasons for pain,

this is a 13-year-old with pelvic pain

and in this case we see an ovary with increased

perfusion lateral to the ovary.

It's important to consider the differential of tubo

ovarian abscess, appendicitis, torsion,

and ectopic pregnancies.

In this case, the patient actually had appendicitis adjacent

to the ovary, but all four differentials need

to be considered when looking at the ultrasound

images presented.

So when we're looking at the child with pelvic pain,

it's important to include the differentials

of intussusception, appendicitis

and inflammatory bowel disease, infected urachal cysts,

omental torsion, meckel's diverticulum,

and even renal stones.

Conclusion

So the presentation of acute gynecological emergencies can

be quite variable and confusing.

Understanding the differential radio findings

and limitations of the exam

are important in the accurate diagnosis

of acute pelvic pain.

Thank you.