What size does lump have to be before showing on mammogram

I would be interested to hear from anyone whose breast cancer was picked up on a mammogram and is very small in size. I have been told that if a lump is less than 1cm it is unlikely to show up on a mammogram. I would like confirmation of this. Also, does an ultrasound show up smaller lumps than a mammogram in younger women? I would like to hear what others have to say on this.

Many thanks.


whoops, will answer on here now, yup, 15mm showed on the mammo then confirmed by ultrasound, Ive got large and lumpy breasts and am just glad that I know them ,and regularly checked as it was only 15mm, could have got a lot larger and prognosis a lot worse as am under 50 and wouldn’t have been in mammo prog for another 5 years .

Sandra x

Same as above. Seen on mammogram which I requested due to dimple on breast. Age 43 - 7mm - confirmed by ultrasound and core biopsy.

Best Wishes LooLoo x x

Thanks LooLoo. This is very interesting. So lumps less than 10mm can show up on a mammogram. Thank you.


Thanks Sandra. I had it all planned what I was going to say to you and the whole lot disappeared. Eeeekkk! Great to hear you were breast aware and you caught your BC at an early stage. My GPs refused me further investigation three times over a four year period saying I had nothing to worry about and as I was under 50 I was not entitled to attend the NHS Screening Programme. I put myself into the system at 50 and was diagnosed with a Stage 3b breast cancer. I’m actively campaigning for better recognition for the under 50s in the hope that my efforts can help others who come after me.

Nighty night.


Hi all I am older than you guys was 52 when dx …Nothing showed on my mammo …the ultrasound picked up the dodgy areas and a further MRI and numerous biopsies confirmed multifocal bc… I went to the docs cos i had boobs that felt like i was pregnant …if that makes sense he told me I was worrying over nothing but I pushed for the hosp …thankfully my breast clinic does an ultrasound as routine …two areas also manifested themselves in my good breast …I have since had mastectomy and recon … xx
So if not happy be a nuisance …I WAS .

Good morning Mazaroo

Thanks for your message. Can you remember what size your lumps were? I ask this because that’s the important bit to my research. I fully understand your quote: “pushed for the hospital” - good on you. This is not how it should be and in most cases we have only learnt to push because of what has already happened. I’m a woman who pushes all the time in light of my experience. I consider this a failing in the system and do not find it comforting or reassuring.

Have a good week-end.


I am kicking myself for not pushing harder and for trusting the BCNs and chief surgeon who are treating me. I found a new lump in my breast after the WLE 2 days before I was due to start rads. They all insisted it was nothing to worry about and dismissed it as a cyst or grainy tissue. I wish I had pushed for an ultrasound then as although I disagreed with them and told them so I decided they were the experts and I should trust them. Now 3 days from finishing rads and the lump is still there. My oncologist felt it and referred me for an ultrasound which showed it was a lymph node and now I need a biopsy which they wouldnt do straight away because I am still having rads. As I went to see them before I started the rads this could all have been dealt with by now and at least I would know where I stood. I bet if it was the surgeons wife or sister they would have had an ultrasound quick smart and not had their worries dismissed as he dismissed mine. I dont want to delay the biopsy but have no faith at all now in the BCNs or the surgeon. Sorry to moan. LooLoo x

Hi, I was 39 when first Dx. My IDCS lump was 3cm, with much wider areas of DCIS around it, but did not show up on my mammogram. I believe when you are younger and pre menopausal can be harder for the mammogram to pick up on lumps due to the difference in the composition of the breast tissue, when compared to older and post menopausal women. It showed up on ultrasound, but even so I had to direct the radiologist as to where it was as he found it difficult to pinpoint. I believe this is why the two methods are often used to back each other up. I hope this helps.

Hi Jeannie

Just put a comment on this on the other post you had asked the question - the posts / timing one,

Me too!

jeannie they were tiny like pin pricks in the cancer breast …peppered all over the entire breast just waiting !!!..3 x 1 cm just under my breast by my ribs…same on the other side …they were so small that the Fine needle used in the biopsy made them break up .hope this helps Maz


Firstly Jeannie and LooLoo - you should be following the complaints procedure to ensure that what has happened to you does not happen to someone else.

I had a delayed diagnosis and the doctor insisted he would do the same all over again so I feel morally obliged to follow this up as a complaint for the sake of other women although it was way too late for me. They DO NOT learn and seldom repent of their errors and incompetence when playing fast and loose with our lives. I wrote to the doctor and then the practice manager and now the complaint is with the PHSO and likely to be upheld given the time it is taking them to reply. If a case has no merit they reply fairly quickly telling you that. The process itself is surprisingly simple. Another lady on this site went to and fro insisting she had a problem and then was dx at Stage 4. She took the case to court and the consultant was ordered to undergo training/supervision - too bad he wasn’t struck off.

Back to lumps on mammos —

I had 2 tumours (not DCIS but IDC) of 1cm and 1inch - neither showed up the mammogram. Mammograms find AT BEST 80% of abnormalities - I was in the 20%. Being in the 20% is not good therefore why bother with mammography? My tumours showed on US scan but they showed as quite larger than they actually turned out to be. At any screening clinic you should have the 3 stage test but this seems only to apply for >50 year olds called as part of the NHS program. If you request screening and can prove a family history then there is a specific NICE guideline which should be followed and if you meet certain criteria you are entitled to an MRI scan.

Hope this helps a bit.

My sister was screened in the US from age 40 and her very tiny DCIS was picked up on a mammogram so now she is a cancer patient because DCIS is not predictable all women with DCIS become cancer patients whether it is appropriate or not. Roll on the day when they can predict what DCIS will do and save many women from unnecessary treatement and surgery.

Hi Dahlia

I am intending to put in a complaint regardless of the biopsy result although I feel quite unhappy that I need to. I would be over the moon to be totally satisfied with the care I have received but this isn’t the first problem I have had. With the previous problems I have been assured that I was unlucky and patients were not normally treated as I have been. I have wanted to give the team every chance to put things right and have been happy with my own surgeon (not the chief one), my oncologist who took my concern seriously and the ultrasound lady. This makes it even more difficult in my eyes for me to complain and I would have probably let the previous things go but this is the last straw!! I hate complaining cos I feel it is ll very stressful and I have had enough of that to last me a lifetime. Nevertheless there is no way they should have dismissed my concern and I was adamant that the lump felt nothing like they described it to me but I was ignored. Thanks for your comments. LooLoo x x

Dear Dehlia

I think I may have had contact with you a long time ago. I am the lady who has been fighting with the system for nearly four years because of my misdiagnosis - attended my GPs three times over a four year period and was told I had nothing to worry about and was refused referral. I put myself into the system at 50 and was diagnosed with stage 3 breast cancer. The complaints procedure, the Ombudsman and the General Medical Council have done nothing for me. In fact they may even have hampered my case. I’ve now taken my case to law. It would be unwise of me to say anything further at this stage. I very much doubt if many (although I do know of one other lady who has been a great support to me) would be able to take their case to law due to the time, effort, stress and costs. The costs to most would be prohibitive - I’ve already spent £10,000 and have still not reached the end of the road. Some would say, why pour good money down the drain. But I feel I have an obligation to do whatever I can to make sure it doesn’t happen again. I do think anyone who is not happy should complain - very important to make sure it doesn’t happen to others. I would like to think the medics would learn from their mistakes but the experience I have had is that they never admit their mistakes and the system + Union is there to protect them.

Best regards.


Mines was not picked up by the mammo, ultrasound or the core biopsy - the lump I presented with was a fibroid and the tumour was hidden underneath the middle of it. Consequently I was told I didn’t have cancer and it was found when I went in as a day surgery case to have the fibroid taken out. The Consultant told me at the check up the following week after he had examined the scar and I was dressed. I knew there was something wrong as he had a breast care nurse in attendance and he kept nervously fiddling with his glasses. I also had a very funny feeling in the car going to the appointment that something was not quite right, it was really strange.

Hi Cherub

I remember you telling me about the Stirling University publishing a study into the experiences of cancer patients in Scotland. Thank you so much for this. I am awaiting the reports being sent to me. I have heard that the CCRC (Cancer Care Research Centre)as it is known is have funding difficulties at the moment which is creating uncertainty. We need organisations like this and I very much hope things are going to be OK.

Thank you.


i also posted similar query on another thread so copied it here:

just happened upon this thread by accident but thought i’d share my experience. Doesnt age factor into how lumps are picked up and the density of breast tissue? At 35 i was on the cusp of ultrasound/mammogram being the most effective so they did both. It seemed that they were able to pick up something on ultrasound but was inconclusive so also did mammogram. Looking back now i think the nurses were pretty certain at this point that it was cancer before even the biopsy. I was one of the ‘lucky’ ones with the positioning of my lump it was quite near the surface near my armpit - it felt massive and you could even see it poking out! I had recently lost weight on my boobs so maybe this had something to do with it as it turns out it was only 11mm. They also picked up some DCIS during WLE which nobody had mentioned previously so i assume this had not shown up on mammogram/ultrasound, it must have been small as they managed to get it all within the margins.
I never really checked my breast before and it was only as i was shaving my armpit that i noticed…it scares me to think how long it would have gone unnoticed had it been elsewhere in the breast.

Futher to that i also experienced delays and certain professionals not taking it seriously at first. Took 8 wks from GP referral to diagnosis…BC ‘specialist’ that i had waited to see for 3 weeks prodded me for 30 seconds and said it was probably hormonal but he’d send me for an ultrasound at a different hospital. So 4 weeks later and during mammogram things started to look more serious…nurses seem to have a way of showing their fears without even having to speak, perhaps they are better placed to be delivering the routine checks and results - leave the surgeons to the surgery! I was then referred back to my original ‘specialist’ and it seems they forgot to book me in on the results clinic, so had to beg and plead and wait 2 hrs to be told i had BC, then he forgot to inform the BC nurse to make a further app as she wasn’t available to speak to at the time!
I’m now with North Manchester general and the whole team have been brilliant, but feel that there must be a better way to speed things up without having to rely on surgeons being the only ones who can be trained to ‘prod’ you and give you the results.
Ta for listening!

Thanks pixielox for sharing your experience with me. I’m sure age factor does play a part in it. I’m always hearing that young breasts are difficult due to their density etc. However, that’s no excuse for refusing anyone access to the system. You were very lucky with regards the positioning of your lump. I could not feel my lump at all. It was there alright but the position was so deep that it could not be seen or felt. I did have swelling, thickening and lumps under my armpit which concerned me but I was told I had nothing to worry about. You sound as if you haven’t had it easy either. I’m very pleased to hear you are having good care under North Manchester General. It is very reassuring when you have confidence in your medical team.

Wishing you well.


Hi Jeannie
Mine was picked up after my first Mammogram aged 50, I was re called usual nothing to worry about for most its … So I returned not really worried and came out petrified second mammogram, followed by ultra sound then biopsy. There was a shadow it was described as calcifications but I think they knew there and then, you can tell by their faces. I was sent away hysterical and had to wait until 4pm the next day Dec 13th! I was then told it was breast cancer it was microscopic according to them and I was “lucky” they had picked it up! You don’t feel lucky at that time. However despite it being microscopic and I’m sure they told me the size, there was 1 node involved so i ended up having chemo. Had WLE (on Dec 31st!!), sentinel node got clear margins.

The ironic thing is I was originally called in the July 2 years ago actually, 3 months before I was 50, and I was away. So I cancelled the appointment, once I had cancelled I could not get back into the system, as they send out apointments according to age and GP surgery I eventually got an appointment at the end of Nov. So of course i will never know if I had gone in July whether it would have been picked up, or if by delaying whether it got bigger that’s one of my What Ifs…
I still have friends who are 50-52 who have still not had their first Mammogram, naturally they are worried. It’s a real lottery isn’t it?