Radiologist - Interview 36

Brief Outline: Dr Michell explains about screening and diagnostic mammograms, calcifications, normal and breast cancer x-rays, ultrasound scans and biopsies.

Background: Dr Michael Michell is a radiologist based at King's College Hospital.

A doctor explains why screening and diagnostic mammograms are taken.

I am Dr Michael Michell and I am a radiologist based at King’s College Hospital, and I direct the screening programme for South East London. And the Screening Programme covers a target population of around 150,000 women aged between 50 and 70 years.

 

So the role of the radiologist is to look very carefully at the routine screening mammograms that are taken and we are looking for any signs that there might be a cancer present. The role of the radiographer, the next person in the team, is to take very high quality pictures so that we can be sure that we have the best chance of seeing any abnormality that is present. And the radiographers and the radiologists and for that matter all of the other members of the multi disciplinary team in screening, all undergo specialist training so that they can do their jobs to the very highest standard.

 

Could you explain why a woman might have a screening mammogram and why a woman might have a diagnostic mammogram?

 

Sure. The screening mammogram is a routine test carried out on well women who in most cases have no symptoms of breast disease at all, and the screening mammogram is offered by the National Health Service as a routine test every three years starting from the age of 50. We invite regularly, every three years up until the age of 70 currently, and after that age women are able to self refer for screening mammograms for as long as they wish.

 

We are currently implementing an extension to the screening programme in this country and that will mean that all women will be invited for their first mammogram before they’re 50, and we will be inviting them up until the age of 73.

 

And diagnostic mammograms? Why would women go for a diagnostic mammogram?

 

So the diagnostic mammogram is part of the test that I used routinely to investigate women with symptoms of breast disease. So, for example, if a woman presents to her doctor with a lump, and she is aged 35 or over, when she goes to the breast clinic she will have of course a consultation and an examination, and then the investigations will involve a mammogram, but will also involve probably other tests such as an ultrasound, possibly a needle biopsy. So the mammogram is part of that diagnostic work up for symptoms.

 

Right. And how often do you give diagnostic mammograms a year, say, compared to screening mammograms?

 

Okay, so a diagnostic mammogram is done as part of the work up for investigation of symptoms, when a women presents to the breast clinic, referred usually by her general practitioner. In most cases doing the whole work up, we are able to make a definite diagnosis and then if treatment is needed then of course we give that treatment. But there would be no follow up after that, so we would aim to get to a definite diagnosis and then act accordingly.

 

Diagnostic mammograms are not part of the NHS Breast Screening Programme, which uses a routine call and recall system to invite well women. However, the same techniques are used in both breast screening clinics and hospital breast clinics for diagnosing breast cancer and many staff work in both settings.

A doctor explains why more mammograms might be taken at the breast clinic.

Some of the women we interviewed said that after they had their first mammogram at the screening unit, they were then recalled to the hospital because they needed more mammograms. Why might they need more mammograms?

 

The screening mammograms are literally a basic screening test. So they may show abnormalities but we cannot be sure in many cases from just looking at the basic screening mammograms exactly what the nature of the abnormality is. And so in order to investigate it further, we need to do further tests and we do those at a screening assessment clinic where the tests will depend on the nature of the abnormality that’s been seen.

A doctor explains what calcifications are.

It sounds very strange to be told that there’s calcium in the breast seen on a mammogram. We’re all used to knowing about calcium in our bones for example. But in fact calcium can be deposited in virtually every soft tissue part of the body, including the breast.

 

Calcium deposits on mammograms are a very, very frequent normal finding. So we probably see bits of calcium on routine mammograms in about a third of the cases that we look at. In most cases it is due to entirely benign normal ageing processes, for example calcification in the wall of arteries, which most people will have heard of. Sometimes calcium in tiny cystic changes, those will be very common findings.

 

When the calcium has a certain appearance however, it may indicate that there is some more serious disease in the breast and it can be the very first sign that we can find on mammograms that there is a cancer developing. The cancer may be inside the milk ducts, and then it is called Ductal Carcinoma in Situ, and what we’re seeing on the mammogram is the calcium deposits which are formed literally inside the little milk ducts.

 

Sometimes, it can mean that there is an invasive cancer present. That’s not something that we’re able to actually see on the mammogram if calcium is the only sign, and that’s something that will be seen down the microscope when we look at tissue.

A doctor explains why some women are given a fine needle aspiration at the hospital.

Some women, a few, less than, but some were given a fine needle aspiration. Can you example why they might have that and what that would show? And what it would involve?

 

Sure, a fine needle aspiration refers to using a fine or very thin needle, which is about the same size as the needle used for doing a blood test for example. And it simply takes a little bit of fluid from where the abnormality is in the breast, and that fluid contains cells which are spread on the microscope slide and then looked at under the microscope. 

 

It is still used in some circumstances, but most clinics in the United Kingdom are now using what is known as a Core Biopsy, and that refers to a slightly different, it’s a slightly, actually a slightly wider needle which takes a core of tissue to be looked at under the microscope. We know from very extensive studies that have been done over the last ten years or so that the core needle biopsy is actually more accurate and gives us more information than the fine needle aspiration, in most circumstances. But both methods are used.

 

This bit of very simple apparatus is what we use for fine needle cytology, where the needle which is the same sort of needle as used for a blood test, is simply inserted into the lump in the breast usually done by ultrasound guidance to make sure that its absolutely accurate, and the needle is moved around within the lump at the same time exerting some suction on the syringe to provide a negative pressure and cells are pulled into the needle, and are then delivered onto microscope slides and then go to the laboratory to be looked at under the microscope.

 

So this is used for some lumps in the breast. It’s also used particularly in patients where we think that there is a cancer present in order to sample the lymph glands in the axilla or the armpit because it’s very important that we have information as to whether there are any cancer cells in the lymph nodes, in order to plan appropriate treatment.

A doctor explains why a woman might be given an ultrasound scan at the hospital.

When women were recalled and they went to the hospital, often they had more mammograms and an ultrasound scan. And several women wondered why they would need an ultrasound scan as well.

 

Sure, sure. When we’re looking at calcification which has been found on the screening mammograms, we do a work up to find out more about it. And the work up includes a clinical examination, usually the clinical examination is normal, so in other words there is not a lump that we can actually feel in the breast. However it’s still important that there’s a clinical assessment.

 

We then take more specialised mammogram pictures which involve magnifying the area so that we can see the little bits of calcium in more detail, and from looking at the shape and looking very carefully at the appearance on the x-rays, we can then decide whether it is a normal harmless finding and doesn’t need to be further investigated, or whether we need to do a further test in order to find out exactly what the cause is.

 

We sometimes do ultrasound in cases where there’s micro-calcification, simply because if we’re able to see the area well enough on ultrasound it means that we can use the ultrasound to guide a needle biopsy. In a lot of cases, however, when the bits of calcium are very, very tiny, it’s simply impossible to see them clearly enough on ultrasound and in those cases we will use x-ray guidance to be sure that we sample exactly the right area when we are doing a biopsy.

A doctor discusses what a normal breast x-ray looks like.

This is a normal mammogram and this would be the same examination in terms of the number of pictures done, whether it was a screening mammogram or whether it was a diagnostic mammogram done in the breast clinic.

 

And we take two sideways pictures and two top to bottom pictures. So this is the sideways image of the right breast, the left breast, and then the top to bottom pictures of the right breast and the left breast. And what we see on the mammograms is two main different types of tissue. The whiter tissue you see here and here is the active glandular tissue of the breast, and the darker tissue you can see here and here is the normal fatty tissue of the breast.

 

And what happens in everybody is that when they are young, most of the breast tissue consists of the active glandular tissue and therefore looks white on a mammogram, and with increasing age more of the breast tissue is fatty and there is less of the glandular tissue. So that means that in a young woman, lets say in her twenties the mammogram is unlikely to be helpful because most of the tissue will be white. And, in contrast, in a woman, a more elderly woman in her seventies for example, most of the breast tissue will be dark and fatty, and therefore it will be much easier for us to see abnormalities.

 

Most abnormalities, whether they are cancers or not cancers, show up as a white area on the mammogram. So that you could, you can understand why if there is a white lump it may be completely impossible to see it if it’s within the white tissue.

 

Also on this normal mammogram you can see, I hope, some rounded very white areas like so, like so, and these are bits of calcification, we call these macro-calcifications, they are very common normal findings and are not indicative of any sort of disease at all.

A doctor talks about breast x-rays that show abnormal calcifications.

This is an example of a mammogram taken during the assessment process in a lady who’s been recalled because of micro-calcification. This is a magnified view so that we can really see the bits of calcium as clearly as we can, and the bits of calcium that we’re looking at are these little white dots just in this area of the breast, and we’ll usually look at these using a magnifying glass so that we can see them as clearly as we possibly can.

 

And by analysing the shape and the appearance of the bits of calcification we can give an indication as to whether it is likely to be due to some malignant disease, possibly Ductal Carcinoma in Situ, or whether it’s due to completely benign disease.

 

When the calcium looks like this, in just one part of the breast, and the little bits of calcium slightly vary in shape and form, we know that there is a risk that this is due to Ductal Carcinoma in Situ. However, we can’t be sure of that just by looking at the appearance of the calcification itself, and this is where a biopsy is necessary in order to obtain tissue so that we can look at the cells and the tissue very carefully down the microscope, and that will enable us to give a definite diagnosis.

 

If this is Ductal Carcinoma in Situ, when we’ve taken the biopsy and looked at the tissue under the microscope, we would then of course be discussing the appropriate form of treatment.

A doctor talks about breast x-rays that show invasive breast cancer.

So for cases of micro-calcification where the calcification is in Ductal Carcinoma in Situ we don’t know unfortunately by looking at the x-ray whether an invasive tumour is present at the same time or not. And we may only know that once the area has been removed at surgery and has all of the tissue has been looked at carefully under the microscope.

 

This is an example of a screening mammogram showing a very tiny cancer, exactly the sort of cancer that we want to pick up in screening practice. These are the sideways pictures, and what we’re looking at is this little area here, which is separate from the glandular tissue, this white tissue that we see on both sides, and when we look at this really closely we can see that it’s got a slightly irregular outline and that’s pretty typical for a tiny invasive cancer.

 

These are the sideways pictures from a screening examination, it’s the right breast, this is the left breast, and in this case there is a little abnormal area here, which subsequent assessments showed was due to a cancer, and this just illustrates the difficulty that there is in interpreting screening mammograms because its quite difficult to pick this area out as different from some of the other white areas, as being abnormal.

A doctor explains what a biopsy can show and what it involves.

Why would a woman be given a biopsy and could you also explain what it involves?

 

Sure. First of all I think we very much understand why women are surprised when we say that there might be something wrong that needs a biopsy at the assessment clinic, because in many cases in screening practice we’re dealing with abnormalities which simply cannot be felt.

 

The biopsy is necessary because even with the very sophisticated and very high quality imaging that we have in the assessment clinic, we’re still not able in many cases to say exactly what the diagnosis is, and therefore be able to advise whether treatment is needed and, if so, what sort of treatment.

 

I, of course, understand, as does the team, how anxious an individual will be when they are told that they need a biopsy. However, they should not be concerned that the biopsy is uncomfortable. We use local anaesthetic for all of the biopsies, and that means that the tissue in the area where we put the needle into the breast in order to take the sample, will be numb, and so after the initial slight stinging sensation associated with injecting the local anaesthetic, after that it really should not be uncomfortable. And if there is any discomfort, then the patient must tell us because we can almost always do something about it, for example give a top up of local anaesthetic. So the biopsy procedure itself should not be the cause of too much discomfort.

 

There are different types of biopsy procedure. And those different procedures vary according to the type of abnormality that we’re looking at, for example can it be seen on ultrasound or can it only be seen on x-ray. And we use slightly different sampling devices in different circumstances. But whichever procedure the particular patient is having, it should be very clearly explained to them what it involves before it’s done.

 

Thank you. Do hospitals give leaflets out, on what is a biopsy? What it involves? Is that something that’s quite standard?

 

Yes, I think in routine practice I would hope that most breast units would send out a leaflet explaining in outline what the tests are likely to involve when women come for assessment. And they should receive that leaflet of course when they receive the invitation to come for the assessment clinic, yeah.

 

This is the needle that is used very commonly in routine practice for taking a core biopsy, and that’s where we obtain a little tissue sample from lumps in the breast, either in a symptomatic clinic or indeed in the assessment clinic. And you can see that it’s got a little, okay I’m going to have to stop and adjust this actually. Alright. There we go.

 

So you can see it’s got a little notch here and that’s where the specimen is collected. And it works extremely quickly, and makes quite a loud clicking sound, and that’s something that we warn patients about before we do the biopsy. And the breast tissue around where we’re doing the biopsy is completely anaesthetised and it makes a click like so. You can see it works extremely fast and with the local anaesthetic does not cause very much discomfort at all, and that’s something that we’ve studied and we know that the degree of discomfort from this sort of procedure is about the same as either having a blood test, or having your blood pressure taken. And so the vast majority of patients tolerate this extremely well.