Sonographic Evaluation of Masses in the Neck - HD

Introduction

My name's Carl Redding, professor of radiology at Mayo Clinic in Rochester, Minnesota.

We'll be talking about masses in the neck, not arising from the thyroid gland.

We're all aware of the importance of masses arising in the central neck from the thyroid gland.

In addition, significant masses can arise elsewhere in the neck as well.

In the next 30 minutes, we'll look at eight commonly encountered non thyroid masses in the neck, their sonographic appearance, clinical significance, and also important differential diagnostic considerations.

Brachial Cleft Cyst

We'll begin with a patient who has a cystic mass in the lateral neck.

Often this mass is a brachial cleft cyst because it's a congenital mass, most patients present at a young age between 10 and 40 years old.

The mass is painless and smoothly, marginated, unless it becomes infected.

It's located in a very location along the anterior border of the sternal cloud mastoid muscle, and at the angle of the mandible.

If we look at the sonographic and CT appearances of this mass, we'll see that it is a slightly thick walled mass with some internal echoes on the ultrasound and in a very, specific location between the sternal colleto mastoid muscle, which is pushed, poster laterally by the mass, the internal jugular vein and carotid artery pushed medially by the mass and the submandibular gland pushed anteriorly by the mass.

The Mr Coronal and sagittal views more, specifically show the location of the mass on the coronal view.

We can see the submandibular gland, displaced, more superiorly by the mass and on the sagittal view, the mass lies immediately adjacent to the anterior aspect of the sternal cleta mastoid muscle.

The vast majority of brachial cleft cysts are second cleft cysts.

We see these again at the angle, the mandible anterior to the sternal cloud mastoid muscle.

The other types of cysts are much less common or rare, and we don't often see these sono graphically.

The treatment of choice is surgical and, because of the propensity of the mast to become infected.

If it becomes infected, it's a more difficult operation.

With the inflammatory changes in the surrounding tissues, this is a different patient who has a cystic mass in the lateral neck.

Cystic Metastatic Papillary Cancer

It's three centimeters in size, and we look internally within the mass.

It has solid nodular components.

And if we look within those nodular components, we can see tiny echogenic foci within them with color or power doppler imaging, we can see that these are vascular and have flow within the solid components, And these findings are worrisome for metastatic papillary cancer.

And indeed that's what, this was in this case.

Another patient with a cystic metastatic papillary cancer, you can see a cystic nodule.

It has some mass effect on the adjacent tissues.

A corresponding bivalve specimen.

It is has a slightly thickened outer wall, some internal nodularity or septations.

It can be purely cystic, particularly in the youngest patients.

And these types of, cystic changes are seen in up to 70% of metastatic papillary nodes.

Differentiating Brachial Cleft Cyst from Metastatic Node

So how can one differentiate a cystic metastatic node from the brachial cleft cyst?

And there's three things that one can do.

First, the brachial cleft cyst tends to lie at a higher level, at level two in the neck at near the level of the carotid bifurcation.

Whereas metastatic papillary cancer can be throughout the internal jugular chain, but when it is solitary or early in the course of the, of the disease, usually it's lower at level three or four along the, mid or inferior portion of the internal jugular chain.

Secondly, one can look within the thyroid gland and often we'll find the primary tumor, in this case a small six millimeter, a mass with internal microcalcifications.

A third thing is that one can do fine needle aspiration of the mass.

It can be sent for cytologic analysis, or more importantly, sent for thyroglobulin assay.

One can simply aspirate fluid and send that fluid if it's a a, a majorly cystic mass or if it has solid components and one is biopsying the solid components, the needle can be rinsed with small amounts of saline.

So after several passes, we have, about a cc or so of blood tinged fluid.

If the globulin is elevated within the fluid, then that indicates it's from a thyroid origin and should be, metastatic papillary cancer or metastatic functioning thyroid cancer.

In one study of 129, such thyroid globulin assays of suspected metastatic disease, most of these were positive, however, some were benign on cytology and four of 11 of those were positive on the thyroid globulin assay.

Also, 16 were indeterminate on cytology, and six of those 16 were positive on th globulin assay.

So it is a more accurate method of determining the nature of a nodule in the lateral neck.

And, in our practice, is become relatively inexpensive and with a turnaround time of just a few hours.

So it really may, if not replace certainly supplement standard cytologic analysis FNA of these lateral masses in the neck.

Another type of metastatic disease that can have this appearance, but often in a different age group of patient, an older patient one can see metastatic squamous cell cancer with internal necrosis, giving it a fluid-filled central area with some internal septations as we see here in blood flow, within them.

But again, that's an often a different, category of patient, not the younger patient that presents with a suspected, or with a cystic mass in the lateral neck.

Thyroglossal Duct Cyst

A patient may also present with a cystic mass in the mid neck.

These are often thyroglossal duct cyst, very similar to brachial cleft cysts.

Again, congenital.

So most patients present before 30 years of age, also painless and smoothly marginated unless they become infected And located in the midline or just off the midline anywhere along the embryologic root of descent of the thyroid.

From the base of the tongue to the base of the neck, two thirds of the time they're located, below the level of the hyoid bone as you see, here in the drawing, although a, a neck extends back through the hyoid and if these are, remove surgically, the surgeon needs to take out that neck through the HIE as well, or else they will tend to recur sonographic images transverse and longitudinal show, these typically as a cystic mass in the upper mid neck on the transverse view, it's display slightly to the side because of the convexity of the thyroid cartilage.

The corresponding CT scan shows the cystic mass buried within the anterior strap muscles, which is a characteristic appearance on the CT scan.

Another thing one it can do in evaluating these cystic masses is to have the patient, protrude their tongue.

And on a real time image, you can see the cystic mass slides with the underlying structures relative to the skin, which shows that it is related to those rather than a cystic mass in the subcutaneous tissues.

Again, further evidence that this is a brachial, or I'm sorry, this is a thyroglossal duct cyst.

These can become quite large and contain internal echoes, particularly if they're infected.

But even non-infected cysts can also have internal echoes.

And because it's of thyroid origin, they can develop solid tissue within them.

As this patient on the right who had unfortunately developed a carcinoma within the thyroid gloss duct cyst,

This is a different patient with a cystic mass in the mid upper neck.

Cyst in Pyramidal Lobe of the Thyroid

We can see this at the level of thyroid cartilage measuring one centimeter in size.

If we look at it longitudinally, we can see the cystic mass.

Again, if we look carefully just coddle to the cyst, we see a tongue of thyroid tissue extending superiorly to surround the cyst.

And what this is, is a cyst within a parametal lobe of the thyroid, which extends up medially from the isus of the thyroid.

And this surprisingly is not uncommon.

Parametal lobes are found in about 50 to 80% of patients.

Sometimes they're very small, but other times can be, quite long.

And it, the importance is that any diffuse pathologic process of the thyroid can also involve the parametal lobes such as Graves' disease, Hashimoto's, or multiple thyroid nodules.

So here if we look at this patient, again, transverse view, if we do a realtime clip going coddly from the cyst, we can follow a thin tongue of thyroid tissue down to the thyroid and you see multiple cystic nodules within the thyroid.

So it's just an additional cyst within the parametal lobe.

So that has a different significance than a thyroid gloss duct cyst, which generally is removed surgically.

This simply represents cyst within the thyroid and could be, followed if it's felt that all of the cysts in the thyroid are of benign nature.

Carotid Body Tumor

A less common type of mass would be the patient who presents with a solid mass in the upper lateral neck.

Here we see a solid structure, two centimeters in size located between the internal and external carotid arteries.

On color doppler imaging, we can see the vessels surrounding the mass itself, which has some blood flow within it.

And this is a typical appearance of a carotid body tumor, an mr.

We can see that anatomic, location more clearly with the mass located between the internal and external carotid arteries and have increased intensity on the T two weighted image.

These are quite vascular tumors.

We can see this on the angiogram.

We can see flow within it on the, Doppler ultrasound exam.

They tend to be one of the most vascular types of tumors within the body because they're situated adjacent to the carotid gland, they, may be palpable or may be pulsatile on palpation.

So the clinician feels a somewhat pulsatile firm mass in the upper lateral neck.

Most of these are sporadic, sometimes familial, they can be locally invasive and can metastasize.

So the treatment of choice is surgical and the cure rate is very high for these.

They also can be bilateral.

So if one sees a mass on one side, it's important to look in both sides of the neck.

And a nice example of a bilateral, carotid body tumor.

Paragangliomas

These are part of a larger, category of tumors called paragangliomas.

These arise from gloma cells, throughout the body.

Many of these are located within the neck, most commonly at the carotid, bifurcation, but in other locations in the head and neck as well.

This individual presented with a palpable mass in the left neck as we it felt to be a thyroid nodule on palpation.

As we look, carefully though the thyroid gland is displaced anteriorly over this hypoechoic, very vascular mass.

And this turned out to be a paraganglioma in an unusual location located posterior to the thyroid gland.

Vascular Causes of Neck Masses

One needs to exclude vascular causes of a palpable abnormality in the upper lateral neck.

A tortuous carotid artery is sometimes misinterpreted as a mass in the neck.

You can see in this older patient how the tortuous vessel lies within just a half centimeter of the skin surface.

And on real time imaging, we can see the jugular vein and carotid artery and cross-section on the left hand side of the image during real time.

Note, the tortuosity of the carotid as it angles towards the skin surface and makes a loop so it can feel, like a mass to the clinician.

Another type of vascular structure.

Here we see a fluid filled mass containing large amounts of internal flow.

This was an internal carotid artery aneurysm.

So important to exclude a vascular mass before, the clinician blindly places a needle into this, type of palpable abnormality.

And occasionally it will represent a vascular abnormality such as these Sometimes a patient will present with a mass in the lateral face and these are often arising from the parotid gland.

Parotid Gland Masses

Anatomically the parotid lies anterior to the ear canal as we see on the anatomic drawing extends cauley and can extend to or even below the level of the angle the mandible.

So it's quite a large salivary gland.

The sonographic appearance, though sometimes the sonographers have difficulty determining the location of this gland 'cause it's very homogeneous and echogenicity a mid-level echo texture and the margins are not clearly seen.

But if one knows where it is, anatomically one can therefore, see the, suspected margins of the parotid gland in this location.

If one develops a mass in the parotid gland, 80% of all salivary gland tumors are located within this gland.

Of those, fortunately 80% are benign, and of those 80% are pleomorphic adenomas.

There are other types of benign tumors.

There are other malignant tumors that can arise within the gland as well.

This individual presented with a palpable mass with the parotid gland lobulated soft tissue mass sono graphically, but it's difficult to characterize these various types of, of salivary gland masses.

Therefore FNA is generally done for diagnosis in this case.

Unfortunately, this was a malignancy within the parotid and surgery is certainly recommended.

Often surgery is recommended for the benign masses as well, just because they can continue to grow and, cause local, compression of structures.

And so they're often removed surgically as well.

But the clinician does wanna know what type of mass they're dealing with within the parid gland.

So the reason to do the FNA sometimes patients will present with bilateral parotid masses this sort of appearance of a chipmunk type of, face with the bilateral swelling.

If we look at this with gray scale imaging, we see multiple hypoechoic nodular areas within the parotid gland.

If we then use color doppler imaging, we see a slightly increased amount of blood flow within the parotid.

So that appearance of the multiple small hypo coic nodules and the slightly increased blood flow.

This is very typical for Sjogren's syndrome.

This is an autoimmune condition that affects the salivary and lacrimal glands.

Usually in women, the patients present with dry eyes due to the dysfunction of the lacrimal gland and a dry mouth due to dysfunction of the parotids.

And sometimes the sonographer will be the first one to make this diagnosis by seeing this characteristic appearance.

If it looks familiar, it is because this is the also a very similar appearance in Hashimoto's thyroiditis in the thyroid gland.

A another autoimmune, type of disease, that affects the thyroid rather than the, than the salivary glands.

On ct, we can also see the bilateral enlargement of the, parotid glands, which are somewhat heterogeneous.

This patient also has a more localized mass within the left parotid gland.

And these patients are unfortunately, prone to develop a type of malignancy within the parotid called a malt lymphoma.

It's a low grade B cell non-Hodgkin's lymphoma.

Sonographic appearance is not well documented, but ranges from small nodules to a more irregular mass as we see here.

And in our experience that is, the typical type of appearance of this.

The patient will often say they have swelling of the glands, but a more localized swelling within one.

And if one, does an ultrasound examination, you would see the more hypo coic area within it and then biopsy could be performed to determine if that is lymphoma.

Submandibular Gland Masses

A patient may present with a mass more anteriorly in the, face and upper neck under the mandible.

These are often arising from the submandibular gland.

This is a more well-defined salivary gland.

We can see it's outline here clearly on the ultrasound exam located deep and just under the mandible.

If there's a mass within it, it's usually easily recognized as in this very hypoechoic area with low level internal echoes.

A small amount of posterior cus acoustic enhancement.

It almost has the appearance of a cyst within the submandibular gland.

But if we look with Doppler imaging, we'll see that there's blood flow indicating that this is a solid mass.

And this is quite a typical appearance of a pleomorphic adenoma.

As we mentioned, this is the most common benign, salivary gland mass.

It's painless and slowly growing.

If it gets large, it can develop atypical features and can mimic malignancy.

So we generally do find needle aspiration for further valuation.

And again, even though these are benign, they're often removed, sometimes they're followed because of they can continue to grow.

And there's some speculation.

There may be rare malignant transformation.

The patient may not present with a palpable mass, but with an abnormality on a PET scan involving the salivary glands.

If we see a hypermetabolic metabolic area, there are a number of types of salivary gland tumors that can have this appearance.

Some malignancies don't have this avidity unfortunately.

So having a lack of uptake doesn't exclude malignancy.

There are also gonna be normal physiologic uptake and gland inflammation can cause uptake.

This is an individual with a normal left submandibular glands.

Yeah, homogeneous.

It appears under the mandible, an abnormal right submandibular gland.

You can see the enlargement, heterogeneity, emus type of appearance.

These patients with s adenitis present with painful glandular swelling.

It can be from a viral or bacterial infection.

So if one sees this enlarged heterogeneous gland with a CORs echo texture, some increased vascular flow, there may be enlarged inflammatory nodes around it.

This is a typical appearance of s adenitis.

Masses in Variable Locations

So we've talked about several types of neck masses that occur in typical locations.

In the last few minutes, we'll talk about three masses that can occur in variable locations within the neck.

Lipoma

One is a lipoma. Certainly we've all seen these sono graphically.

They're very common soft tissue tumors.

They can be anywhere in the body but frequently are found in the neck, often in the posterior triangle.

They are benign, composed of fatty tissue. They're painless.

Soft mobile.

If we see these sono graphically, they have a variable appearance, but usually the echogenicity is similar to surrounding tissue and importantly, there's no internal blood flow on Doppler imaging.

They're also very soft.

So on this realtime example, if one presses this mass deep to the overlying musculature, you can see it deform because of its very soft nature.

So if we see a mass without and with compression that deforms like this, that's more, information that this is should represent a lipoma.

Sometimes it's unclear sonographic, this oval mass had two different types of echo textures within it.

The patient went on to have an MR scan or CT would work as well, showing the fatty nature of the tissues.

Just two, different types of areas within it with a high signal from a fat, type of components.

Epidermoid Cyst

Another type of mass that can present in the neck is an epidermoid cyst.

There asymptomatic, slowly enlarging can range from just a few millimeters to up to five centimeters in size.

They have multiple internal echoes.

Importantly, they have no internal blood flow on color doppler imaging because they're filled with an oily substance without, blood flow within it.

Sometimes they can have a, an extension to the skin surface.

We don't see that on this particular image, but this is due to the reason that the top layer of skin grows into the middle layer.

To form these epidermoid cysts and causes a blockage which forms the, fluid type component within it.

They're usually asymptomatic, but if they rupture they can cause significant discomfort.

This cyst was fairly large.

CT ended up, being performed, which shows the fatty and oily nature of this substance of decreased attenuation.

This patient presented with a mass, a different patient in the left neck, felt to be a thyroid nodule, but if we look at the location of the mass, the thyroid is deep to that and the strap muscles are between the mass and the thyroid.

So certainly this is not a thyroid nodule, it is a mass in the superficial soft tissues of the neck.

And this because of its size, it did go on to a, a biopsy, but that obtained material that was consistent with a benign epidermoid cyst.

Neurogenic Tumors

Finally, one will also encounter neurogenic tumors in the neck.

Here lateral to the right carotid artery and internal jugular vein, there's a rounded soft tissue mass.

This was a schwannoma arising from the right phrenic nerve.

If we look at the mass in a longitudinal view, sometimes you will see the typical tail or dumbbell shape of this mass on ultrasound, there's a small amount of internal flow within it.

I An MR imaging with gadolinium contrast material.

It has an in homogeneous enhancement pattern, quite typical of a neurogenic tumor.

If one places a needle into these masses, particularly in patients that have had previous neck surgery where there's a traumatic, neuroma, they can be quite sensitive.

If you do take several minutes to slowly instill a lidocaine around the edge of the mass or into the periphery of it, the patient will let you then place a small needle into the periphery of these masses and you can obtain cell material that, again is characteristic of a neurogenic tumor.

Summary

So in summary, we've looked at several types of common neck masses, some that arise in characteristic locations because of the structures they arise from others that arise in more, variable locations.

And with the combination of their sonographic appearance and sometimes with the assistance of finding needle aspiration, we can often make a specific diagnosis of these types of neck masses.

And I hope that there is information here that will be helpful in your practices.

So thank you.