Lumps and Bumps - HD

Introduction

Hello, I'm Jason Wagner from the University of Oklahoma.

My talk regards ultrasound of lumps and bumps.

Certainly a common patient complaint, something we're asked to do a lot, and something that can provoke some anxiety among some ologists.

Ultrasound is an excellent way to evaluate superficial lumps and bumps.

Financial Disclosure

With regard to this lecture, I have no relevant financial relationships to disclose.

Diagnostic Algorithm and Talk Outline

This is the diagnostic algorithm that we use in the ultrasound evaluation of a lump or a bump.

And this is also the outline for this talk.

We'll go through all the aspects of this algorithm, beginning with the clinical exam and ultrasound evaluation of a superficial lump or bump for this evaluation.

Clinical Exam and Ultrasound Technique

We begin with a focused history and palpation of the lesion.

This is very helpful in establishing a differential diagnosis.

For the ultrasound examination, we usually use a high frequency linear transducer to begin with.

And in certain parts of the body, such as the thigh and the trunk, it's important to also use a low frequency transducer to make sure you're not missing something deep.

A mound of gel and a light touch are important, and it is good to correlate palpation of the lesion with ultrasound, just like you would do in a breast ultrasound to confirm that you are imaging the thing that is palpable.

Case Example: Importance of Looking Deep

This case is an example of why it is important to look deep.

This was an elderly female who presented with a groin lump, and you'll see here on this image taken with a high frequency linear transducer that there is a normal appearing fatty, replaced inguinal lymph node.

However, the deep tissues do not have a normal appearance.

When we subsequently looked with a low frequency curve of linear transducer, we saw this large, round, solid partially cystic mass that is seen here on this subsequent contrast enhanced CT performed because the patient had a contraindication to MRI and unfortunately for this patient, this was a large sarcoma, which could have been missed had we not looked deep.

So in the thigh and in the trunk, it is important to also use a low frequency transducer and look deep.

Extended Field of View and Color Doppler Optimization

An extended field of view scan can be very helpful with superficial larger lesions such as this fairly large deep subcutaneous lipoma.

Colored doppler is an important part of this examination, but it needs to be optimized appropriately.

And the three major parts of optimizing this are number one, to decrease the scale.

Number two, to increase the gain, and it's helpful to potentially increase the gain all the way up to significant flash artifact and then slowly decrease the gain to where there's only a minimal amount of artifact.

And then finally, to not use a heavy hand.

These two images are both taken with optimized scale and gain.

The only difference between these two images is the amount of pressure placed with the transducer.

And this was not a large amount of pressure, it was just allowing the weight of the transducer to be transmitted onto this small superficial normal lymph node.

And in this subsequent image, the weight of the transducer is picked up off the lymph node, barely maintaining skin contact.

And you can see that we see blood flow much better.

Lesion Localization

Lesion localization is key for establishing a differential diagnosis and establishing therapy.

In many cases, the major components that you should be aware of are the epidermis, the dermis, the subcutaneous fat, the deep fascia, and then the muscle below it.

And localizing a lesion into those particular levels is very helpful.

For instance, this is an intradermal squamous cell carcinoma.

This is within the subcutaneous fat and just was a seroma.

This is something you don't see very commonly, but this is an interfacial lesion actually associated with fasciitis from M sen infection.

And then this is an intramuscular tumor that we'll talk about later.

And here again, the levels, dermis, subcutaneous, fat, deep fascia, and then muscle.

Possible Results of Clinical Examination and Ultrasound

So now going to the possible results of the clinical examination in ultrasound, first of all, and not uncommonly, we see no sonographic abnormality.

Usually this ends the issue and we just recommend clinical follow up with a repeat imaging if there's a concerning change.

However, in rare circumstances, if there's something really suspicious about the patient's history or the examination, we will suggest an MRI or a ct.

Specific Non-Neoplastic Diagnoses

The next possibility is making a specific non neoplastic diagnosis.

And it's important to recognize that a good portion of things that present as a lump or a bump are not a neoplasm.

And we're gonna go through all of these specific non neoplastic diagnoses before we end up with neoplasms at the end of this discussion.

Foreign Bodies

So beginning first, with foreign bodies, foreign bodies are well visualized with ultrasound in most situations.

And certain things such as wood can be very difficult to visualize with x-ray and ultrasound is the preferred modality for evaluating these.

Here you see a small little splinter.

Here's a much larger piece of wood.

You'll see in both of these, there is an echogenic structure with some deep shadowing, but with both of these, the deep shadowing is observed better when the transducer is oriented perpendicular to the long axis of the foreign body.

And then you can see the shadowing better.

And this looks really a lot like an intrauterine device because that is a foreign body.

Here's a piece of metal and a piece of glass, metal can have either deep shadowing or a reverberation type artifact.

And glass is more common to have a reverberation type artifact.

But the common theme with foreign bodies is an echogenic structure with deep disturbance of the sound beam.

Here's an example. In a movie of a metallic foreign body, there's a little twinkle artifact with color.

You can see as we go through this movie, there are parts of this foreign body, which shadow and parts of it, which have a comet tail artifact.

And this is a bullet in the supraclavicular fossa, as you can see on this chest radiograph going on to hernia.

Hernias

This talk does not extensively discuss abdominal hernias such as umbilical and inguinal hernias only to make the point that if you are imaging a lump in an area where a peritoneal hernia is possible to make sure that it's not a hernia, because the treatment for a lipoma and a hernia are quite different, it's important to make that differentiation.

Some things to note about hernias, they often will change in size, but not always change in size with maneuvers such as Valsalva and upright imaging, and not uncommonly, you'll see some shadowing at the edge of a hernia or in the neck of a hernia.

And that is a feature that is not seen usually in lipomas, which can be helpful in differentiation.

Another hernia to consider is a muscle hernia not as common, at least in my practice as the peritoneal hernias.

However, it can be seen, particularly in the anterior shin.

The most common location is involving the tibialis anterior mid shin where this muscle herniates through a small gap in the deep fascia, with muscle tissue extending into the subcutaneous tissue.

Often this little gap occurs where a small perforating artery goes through the fascia.

And the classic history here is a painful lump that only occurs with exercise.

And so to get this image, I actually had this patient run a couple laps around the building and immediately come back in and we could image this for a few minutes and see this little muscle hernia.

Ganglion Cysts

The next specific diagnose to consider is a ganglion cyst.

These are pretty common, particularly around the wrist, however, they can occur in many locations in the body, as expected with the cyst, it's predominantly koic with some through transmission and no internal blood flow.

However, ganglion cysts often have these partial septations may have some internal debris.

If you look closely enough, you can often see the connection of the cyst down to an offending joint or to a tendon sheath.

An important thing about a cyst is to be suspicious when you see something that looks like a possible cyst in a location where a cyst is not expected, basically not near a joint.

This looked kind of like a cyst, but it was in the supraclavicular fossa, which is an unusual place for a cyst.

And when we optimized the gray scale and turned on colored doppler, we found this was a solid mass related to lymphoma.

Both lymphoma and melanoma are well known for potentially being essentially anti coic on gray scale imaging.

Lymph Nodes

Lymph nodes, lymph nodes are certainly a common cause of lumps and bumps, particularly in the neck and other locations such as the groin where lymph nodes are expected.

It's important to remember that lymph nodes can occur in other places, including around the elbow.

I will not talk extensively about lymph nodes only as a brief comment to remember that history and morphology trumps size when evaluating a lymph node, for instance, this is a quite large lymph node, almost four centimeters, in a teenager with mononucleosis.

Whereas this lymph node is barely enlarged.

However, it does not have a fatty hilum, unlike this one.

And it's in an elderly male with a history of squamous cell carcinoma.

And this was metastatic squamous cell carcinoma.

Bone or Calcification

Occasionally, when evaluating a lump or a bump, we'll see something that looks like bone or calcification, where you have an echogenic reflector and then shadowing afterwards.

I think that's about all you can often say with ultrasound.

And in cases where you see something like this, getting an x-ray can be very helpful.

And occasionally we'll put a marker by palpation or ultrasound over the area to help us with interpreting the subsequent x-ray.

In this case, a 52-year-old male who did what many of us need to do and got on the treadmill and lost 50 pounds.

But then he felt this hard neck mass, which of course made his doctor very concerned, who heard it opposite hard neck mass weight loss, worried about cancer.

But in this case, this thing that looks like a bone was a bone, it's just the cervical rib that this poor guy probably couldn't feel for the last three decades because of his extra 50 pounds.

This was a 42-year-old male who had right upper quadrant pain.

Initially we just did a gallbladder sonogram, which was entirely normal.

But then in further talking to the patient, he said, well, it hurts a little more superficial.

And as we were doing intercostal scanning, he had some pain.

So we looked with a high frequency linear, and we see this rib has a focal bulge in it with some curve of linear echoes.

We put a marker and did an x-ray.

And you can see that there's actually two adjacent healing rib fractures.

A couple other examples of the same idea.

This is a 14-year-old with a hard mass posterior lower skull.

You can see what looks like a bone continuous with the skull, and it is a normal variant, a prominent occipital protuberance.

And then finally 19-year-old with a hard mass lateral aspect of the knee.

Again, you can see bone here continuous with the adjacent distal femur.

And when we got an x-ray, you can see a classic osteo cdr.

Actually, what we're doing here just for a little extra credit, is measuring the thickness of the cartilaginous cap.

That's part of the osteo kdr.

Fat Necrosis

Briefly mentioning the difficult, in my opinion, subject of fat necrosis.

This is not rare.

It can occur just about anywhere in the body.

It can be painful, it can be a firm mass, and it can be a diagnostic challenge.

Here is a large example of fat necrosis within the anterior abdominal wall, which we were worried enough about to biopsy, but it confirmed fat necrosis.

Here is fat necrosis in the female breast with corresponding classic mammographic findings.

And this is an area of fat necrosis after trauma in a young patient at the lateral aspect of the knee.

This had also classic rem calcification on an x-ray with fat necrosis.

In my experience, it's fairly common to see some degree of shadowing.

However, that is not true in all cases of fat necrosis, and that has not been consistently reported in the literature.

My opinion on fat necrosis is it can be a challenging diagnosis.

But the common thread is that it is altered subcutaneous fat that is palpable, may or may not have some shadowing, and may or may not be painful.

Sometimes this is a difficult diagnosis and requires biopsy.

Epidermal Cysts

Moving on to epidermal cys, also known as epidermal inclusion cysts, or the not exactly correct term of sebaceous cyst.

These usually have a fairly classic clinical history of a lump that may be slowly growing, but has been there for a while and is usually non painful.

With sonographic evaluation.

If you're lucky, you can see the dermal extension of this lesion, but it should always touch the dermis.

They should be well-defined.

They often have enhanced through transmission, and they have been described to have this pseudo testis type pattern of internal echogenicity.

Occasionally you'll see a fluid debris level, although that's not very common in my experience.

You should not see internal blood flow within these lesions.

And if they get large enough, sometimes you can actually see these internal hypo coic shard like structures, which are probably the cholesterol crystals forming within the epidermal inclusion cyst.

Now, these can be a real diagnostic challenge when they rupture.

It's helpful if you can get the history of a preexisting non-painful lump that became painful.

However, absent that history, these can be really confusing, because now they have internal blood flow.

They have some surrounding cellulitis or inflammation of the subcutaneous fat.

They're now irregular in shape, and they can certainly be confused for a more aggressive lesion.

These lesions will not uncommonly need surgical excision, both for diagnosis and for treatment, because these have a propensity to have multiple recurrent infections if they're not treated surgically.

Abscess

Moving on to an abscess.

Very common for us to be asked to do an ultrasound to evaluate for abscess in the setting of cellulitis.

Here are examples of multiple abscesses from a small abscess to more extensive subcutaneous abscess, a deeper axillary abscess.

You'll see that the contents range from hyper coic to very hypoechoic.

I have become convinced that the most important maneuver that you can do when looking for a superficial abscess is differential compression and release of compression.

This is a large subcutaneous abscess that is difficult to see on this static image because the contents are essentially iso coic to the adjacent subcutaneous fat.

The contents are hyper coic, but when there is placing of pressure and then release of pressure, you can see this much more clearly on dynamic scanning.

Of course, you can also use ultrasound to sample the fluid collection for diagnosis and in some cases with smaller collections for definitive treatment.

Here's another example of intramuscular abscesses.

This is all abscess, and this is abscess.

You can see the motion of this fluid, again with differential compression and release of compression.

What's important about this to drive home the point, this is abscess that is hyper coic.

This is abscess that is nearly koic, both from the same bug.

I know because I aspirated both of them and both in the same muscle group in the upper arm.

So the contents of an abscess can range from hyper coic to nearly koic.

Cellulitis

The differential diagnosis is often uncomplicated cellulitis.

Here's a good example of focal cellulitis where you get thickening and increased echogenicity of the subcutaneous tissues, some adjacent edema, some dermal thickening.

Here's the correlating MRI and then a couple other examples of more flagrant cellulitis with a lot of expansion and hyper genicity of the subcutaneous fat and small areas of edema without a oculd or defined fluid collection.

This case is just to remind us that not every superficial collection with mobile internal debris is an abscess.

Unfortunately in this gentleman, this was a large deposit of metastatic melanoma.

But you'll see that there is not thickening or inflammation of the adjacent overlying subcutaneous tissues and dermis.

And there is both mass and heterogeneous mobile fluid within this lesion.

Hematoma

Finally, hematoma, hematomas of a range of sonographic appearance.

If you see one in its very acute setting, such as when you cause it while doing a biopsy, you'll note that it is often quite echogenic.

It can be hyper coic even.

As it goes through the process of evolution, it usually becomes more hypoechoic.

It can have the linear, almost lace like pattern that you're used to with a hemorrhagic variance cyst.

But it can have multiple different patterns.

Here you see several postoperative hematomas.

This is a small hematoma anterior to the tibia from dropping a weight on the shin.

I'm sure that hurt. This is from a Lovenox injection, and this was minor trauma producing a big hematoma about the elbow.

However, the patient's INR was greater than eight.

So although these have varied sonographic appearance, the common thread with all of these cases is that there is a good explanation for hematoma.

In my practice, I get very suspicious of a possible hematoma unless there is a good explanation.

There's another case of an ill patient with an elevated INR with acute onset of a large thigh mass.

Again, we started with a high frequency linear transducer.

We saw some subcutaneous edema, and then unusual appearance of the deep tissues, but no definite collection with the high frequency transducer.

So again, this is the thigh. It is important to look deep.

And when we looked deep, there was this large heterogeneous collection that was somewhat ellipsoid following the muscle.

And in this case, on a subsequent non-contrast CT had high attenuation and given the history was compatible with a large hematoma, consider this case though 56-year-old female.

She was otherwise well patient with a painless firm thigh mass, which she attributed to recent minor trauma.

She reported that she had whacked her thigh against the corner of her desk while at work.

Well, I wasn't buying this for hematoma for two reasons.

First of all, her story was not very convincing.

I don't really believe that it is common that an otherwise healthy patient on no anticoagulation will have a spontaneous intramuscular hematoma associated with minor trauma.

And secondly, the color doppler was not optimized.

You see, there's no artifactual color being written whatsoever.

So I went and took a look at this patient myself.

Here you can see I reduced the scale. I increased the gain.

There is lots of flash artifact, but it allowed me to see this vessel, so I knew where to put the pulsed box, got arterial flow, and therefore we knew this was actually a solid mass.

Subsequently the patient had a contrast enhanced MRI, which showed it was an enhancing mass.

Fortunately for this patient, it was a benign mix, but I submit to you that this could certainly have been a sarcoma as well with this appearance.

And just for comparison, this is one of the postoperative hematomas that I showed recently.

And I would argue that this and this look basically the same with the exception of the internal blood flow.

And this is the reason why intramuscular hematomas give me heartburn, specifically when the situation of delayed diagnosis of a sarcoma has been evaluated in the literature and when an incorrect diagnosis by ultrasound has been the offending reason for delayed diagnosis.

The most common diagnosis by far is intramuscular hematoma or muscle tear, specifically 11 of 14 cases in the two articles I found addressing this subject.

The other incorrect diagnoses were abscess and pseudo aneurysm.

Interestingly, lipoma is not on this list.

We'll get to that later. So in my opinion, hematomas require an explanation, significant trauma and or anticoagulation.

And if there is any doubt, you should consider biopsying or following a hematoma.

Also, remember that many sarcoma patients report first noticing their mass after minor trauma, just like testicular cancer patients.

Here's an example of a large intramuscular lesion in the thigh.

This patient did have some anticoagulation, although not excessive anticoagulation.

The patient did have an mr, which was not entirely definitive, and therefore we elected after a consultation with an orthopedic oncologist to biopsy this lesion, which confirmed a hematoma.

Now, in my opinion, even after this biopsy, this lesion should be monitored to make sure that it goes away or follows the expected course of a hematoma, which could be myositis Pacific hands.

And here's a reason why this is an unfortunate 76-year-old gentleman who had this large thigh lesion.

So is this a sarcoma? Well, yes. Is this a hematoma? Yes, because it is a hemorrhagic sarcoma and some sarcomas do this, they're often bad acting aggressive sarcomas, but they look like hematomas because they are hematomas within a sarcoma.

Biopsy of such a lesion can also be quite difficult because unless you hit the viable tumor, you're just going to get hematoma.

Neoplastic Lesions

Which leads me to mass like lesions that we find with sonographic evaluation of superficial lesions in this area.

We must first ask the question if you see something that you think is a neoplasm with ultrasound, is it worth going any further?

Can ultrasound meaningfully characterize mass like or neoplastic lesions in the soft tissues?

Well, that's a very good and important question that has been evaluated with several studies in the literature, including this study published in 2004 out of Michigan, which found suboptimal accuracy and other study out of China in 2013 also found suboptimal accuracy.

The study that my colleagues and I did, published in JUM in 2013, we found pretty good performance of ultrasound when we compared the initial diagnosis with the subsequent pathology.

So what's the difference in our study and the other studies?

Well, there are several differences.

One of the differences is that in our study, almost all of the lesions were subcutaneous rather than intramuscular.

And secondly, we did not require that ultrasound make a specific PA or histologic diagnosis, for instance, re differentiating between the subsets of lipoma.

That wasn't a requirement in our study.

Only that in our study, we looked to see if ultrasound was able to put things in large categories that would guide management the most useful clinical research study addressing this subject, in my opinion, was published in 2009 by a group out of the uk and they looked at 385 consecutive patients referred to a sarcoma tertiary center for evaluation of a lump.

All of these patients had ultrasound and were triaged into a benign or worrisome category.

The benign category included lipomas that had no concerning features were subcutaneous and were five centimeters or less in size.

And 79% of these 385 patients were categorized as benign findings and sent back to their referring physician for clinical follow up.

Some of these patients did bounce back for additional follow up, but none of them had evidence of malignancy.

At a two year follow up evaluation, the remainder of the patients 21% were triaged to additional evaluation, and most of them got mr.

Of that six were found to have sarcomas or a total of less than 2% of the initial patients.

Which reminds us that although some patients presenting with a lump or a bump will have sarcoma, it is a small minority of the patients.

And what were the worrisome features that led them to get an mr?

Well, any mass greater than five centimeters or in a deep location, which basically means intramuscular a painful or enlarging mass, a lipoma with strange sonographic features or masses that do things like distort the tissues or have disorganized flow.

So if you find something that looks like a neoplasm, the first and simple thing is to measure it and see where it's located.

If it's greater than five centimeters or it is deep to the fascia intramuscular in almost all cases, an MRI is the next appropriate imaging test.

Although a CT can be useful in some body sites or if the patient has a contraindication to MRI, but if it is a superficial mass less than five centimeters, I think the very helpful differentiation to guide management is whether or not it is characteristic of a lipoma or not characteristic of a lipoma.

Because in general, things that are characteristic of a lipoma and superficial in less than five centimeters, in my opinion, do not necessarily need to be excised.

That is based on other factors.

However, most of the things that are not characteristic of a lipoma will at least be seriously considered for excision or needle biopsy or in some cases additional imaging.

Lipoma

So let's look at lipoma.

It is by far the most common soft tissue tumor.

It is estimated that 300,000 lipomas come to clinical presentation each year.

This is in contradistinction to 10,000 soft tissue sarcomas presenting through in all body sites each year.

Most lipomas are subcutaneous in location.

They're most common in middle to late adulthood.

They are rare in children, although they certainly are seen in older teenagers and they're multiple in 5% of patients who have lipomas.

So what are the sonographic features of lipoma?

Well, echogenicity isn't terribly helpful because they range from hyper coic to hypoechoic, but they should have smooth borders.

Sometimes this is better seen on real-time imaging.

They should have no refractive or edge shadowing, no deep shadowing.

They may have some deep acoustic enhancement.

They should have minimal or no color doppler signal.

They generally have these wavy echogenic internal lines, but otherwise have uniform echogenicity.

They are wider than tall, usually quite a bit wider than tall in the subcutaneous tissues.

So if you see something that is spherical, it is in my opinion, very unlikely to be a lipoma.

They are usually subcutaneous in nature, not intradermal, and they are oval or lobulated in shape.

And clinically they tend to be rubbery and slow growing.

They are usually not painful with a few exceptions, including angio lipoma and lipomas that happen to be in a location such as near the belt line where they get rubbed by clothing.

So looking further at these wavy echogenic lines, both the study that I did and another study that's been published found that these wavy echogenic lines are generally only seen in fat containing structures such as lipomas or fat containing hernias.

This is an example of a lipoma with wavy echogenic lines, another lipoma that is quite a bit wider than tall with wavy echogenic lines.

This looks potentially like a lipoma with wavy echogenic lines.

However, when we look further, we see that there is an area of deep shadowing, which is the neck of this fat containing hernia.

So regarding echogenicity of lipomas, as I said, they can range from hyper coic two hypoechoic, and this is the range that we found in the study that we did.

All of these nine lesions are path proven excised lipomas, and you can see they range from hypoechoic to hypoechoic with respect to the adjacent subcutaneous tissues.

There are some pathologic variants of lipoma.

The most common is angio lipoma, which most commonly occurs in the upper extremity.

It may be painful, which is unusual otherwise for lipomas.

And in my experience and in what's been reported in the literature, they tend to be hyper coic.

There are multiple other less common pathologic variants of lipoma including fibro lipoma.

All of these pathologic variants, however, are benign and are treated similarly.

Liposarcoma

So what about lipos sarcoma?

Are we gonna kill people right and left by suggesting the diagnosis of small subcutaneous lipoma?

Well, I think the answer to that is no.

Most cases of lipo sarcoma occur in the deep tissues, intramuscular within the extremities or in the retroperitoneum where they are potentially aggressive diseases that cause patient death.

Subcutaneous lipos sarcoma, however, is a rare disease.

And in several pathologic case series that took many many years to accumulate at large centers, the lipo sarcomas, both well differentiated or the so-called atypical lipoma and pleomorphic lipo sarcoma were found to have occasional local recurrence but no distant metastasis.

So subcutaneous lipos sarcoma is a rare disease that has been reported to have an indolent course different than deep lipos sarcoma.

So in my opinion, a subcutaneous lipos sarcoma that meets all the sonographic criteria for lipoma should be very rare.

When I diagnose subcutaneous lipoma with ultrasound, I recommend clinical follow up with repeat evaluation if there is significant growth of the lesion or any other concerning clinical change.

And in my opinion, if you wanna worry about an adverse outcome from delayed diagnosis of a sarcoma, you should worry about intramuscular hematoma, not subcutaneous lipoma.

Other Superficial Masses Less Than Five Centimeters

So what about the things that do not look characteristic for a lipoma but are superficial and less than five centimeters?

Well, in my opinion, it's hard to tell what most of these things are, and it is difficult based solely on the sonographic features to make a specific histologic diagnosis.

Occasionally there will be some sonographic features that are helpful.

If you're lucky with a nerve sheath tumor, you can see the nerve coming in and out of it and suggest that it is a neurofibroma or possibly a schwannoma.

There is some literature suggesting that the pattern of how it interacts with the nerve can help you differentiate the two.

I have not found that to be helpful in my practice.

However, I have not seen a large number of peripheral nerve sheath tumors.

Most of the other lesions that you will encounter are similar in appearance.

Hypo coic, solid lesions with internal blood flow that do not have the wavy echogenic lines you see with lipoma, most of these lesions are probably just best excised.

In some situations a needle biopsy can be helpful, particularly if the patient has a history of primary carcinoma or other malignancy that has a propensity to metastasize to the subcutaneous tissues.

In rare cases, MRI may be helpful, but with these small little lesions in my experience, excision is just the best way to deal with it both diagnostically and therapeutically.

And here are some examples of metastatic lesions as well.

Occasionally, however, there are features based on the location and the history of the lesion that can strongly suggest a specific diagnosis.

For instance, this is an aggressive looking heterogeneous infiltrative looking solid lesion with some blood flow in the anterior abdominal wall.

However, it is a young woman and it is right next to the scarring from a fan and steel incision.

And when talking to the patient, this hurt most during menses.

It was proven as expected to be endometriosis in the anterior abdominal wall.

This is a solid lesion with some internal blood flow hypo coic, well-defined, not entirely specific based on its ultrasound appearance alone.

However, the history and location being located along the flexor tendon sheath, slowly growing, painless finger mass, strongly suggests a giant cell tumor of the tendon sheath, which is what it was.

You will occasionally encounter soft tissue.

He angios, which in the soft tissues look entirely different than they look in the liver and other parts of the body, in the hand and wrist.

They can be fairly well-defined lesions.

They often have some degree of internal blood flow, and they may have this unusual history of a mass that fluctuates in size on each individual day.

Here are examples of larger human angios in four different patients, when they're outside the hand and wrist in the more proximal extremities.

It's been my experience that they can be fairly ill-defined, infiltrating looking lesions, they can have internal blood flow, and occasionally you'll see shadowing associated with bolus.

Finally looking at some metastatic lesions in addition that can occur in the subcutaneous tissues.

Here's an example of a deposit of metastatic melanoma that has mixed echogenicity as solid and some other examples of metastatic melanoma.

Take Home Points

So the take home points from this talk.

First of all, real-time imaging with compression is very helpful in detecting soft tissue abscesses.

It's a requirement when doing a scan for this at my institution.

Secondly, make the diagnosis of intramuscular hematoma with caution.

The appearance of sarcoma and hematoma certainly overlap.

Solid masses that are deep to the fascia or greater than five centimeters often require further investigation.

Usually this is with MRI.

And finally, in my opinion, small subcutaneous lipomas can be diagnosed with ultrasound and can be managed with clinical follow up.

And I thank you for your attention.