Can cancer lumps suddenly appear overnight?

yes, but it is much more likely that non-cancerous ones would. Age 39 is prime perimenopausal territory when hormones start changing again and fibrocystic stuff kicks up.

cgood75 - Try not to worry too much about it.  Really.  I started finding lumps when I was about 40 and I had developed fibrocystic breast disease - strictly hormonal and benign, but literally a pain.  They would show up one day and most would just eventually disappear in a few days / weeks.  I would have three or four or even a dozen lumps in each breast at any given time up until my BMX.  My diagnosis and surgery for bc had nothing to do with those cysts but now that I've gone through what I did, a big bonus was to get rid of the pain from those little suckers, believe me!  I think you should definitely get it checked out by a doctor, but because of your age, would suspect that it really is hormonal.  Wishing you the very best... and please let us know how it goes!

Can the cancer grow up faster if you are pregnant?

Melissa: i asked because my lump appeared overnight too while pregnant, so I thought it was possible

Also, aggressive doesn't always mean "bad." Chemo targets fast-growing cells the best. That is IF it is cancer. Remember that something like 90% of lumps are benign.

I just wanted to say the thing has happened to me. Popped up one night did the pesky little things, I have three of them, I have been totally depressed since October and only now going to see my doctor next week, they are like little marbles that move when I touch them. I think they are cysts. 

mine are bottom near the sternum. About 0.5 cms? Some days they feel firm and other days rock hard. I had a cyst in September and ultrasound, but it showed nothing. So I don't think a cancerous lump would have grown in one month, when I found them in October. If so at the growth rate in one month then I assume they would be massive right now. I hope your ok :-) and try not to worry about it 

I'm not a doctor, so this is just based on what I have read and know. First, IBC presents differently than most other breast cancers - and it is rare - so for now let's put that aside. As far as lumps are concerned, it's important to remember how cells 'grow'. They grow by division (so a doubling of cells). So lets say you start with 4 cancer cellls - that becomes - 8, 16, 32, 64, 132, 264, etc. - from what I have heard, most (not all) double in size over the course of a month (and yes, pregnancy speeds up this processes). So you can imagine that a cancer 'mass' that is 1/2 the size of a marble and can likely not be felt and which has taken a very long time to get to that size, can double in size during a months time and be felt 'overnight'. I could, once I felt my 'lump', feel it grow during the two weeks that I waited for diagnosis. I could also feel it shrink when I had neoadjuvant chemo. 

I will (surprisingly) question one thing Beesie said - because she is REALLY good at this stuff. As far as I know cancer grows quickly relative to 'other' cells. Now certainly this is different than say a cyst- where you can have something swell vastly overnight. The reason I say this is because chemo attack fast growing cells (or fast dividing cells if you will). This is why people lose their hair during chemo - because hair cells are fast dividing, our intestinal tracks can also suffer. And - the fastest growing hair falls out first, and the slowest growing last - sometimes not until chemo itself is over. 

All that said - things that are round & marble like are most often cysts & I will keep my fingers crossed tight as can be that whatever you are feeling, it's benign. 

i just felt another lump in a different spot...same breast that I have pain in...I just had a mammo and ultrasound on Tuesday and they did not see this? This new lump is pretty big and hurts (((  

Trisha, I just felt it just now and it was not there yesrerday when I had a mammo and ultrasound done....and my onc gave me a full breast exam ((  it was not there and it hurts ....

ziggypop, I think we may both be right.  I agree with you completely that relative to normal cells, cancer cells grow quickly.  But 'quickly' is a relative term. 

This study found that on average it took 1.7 years for a breast cancer tumor to grow from 1cm in size to 2cm in size.  Of course there is variance.  Approx. 5% of tumors achieved this growth within less than 1.2 months, whereas another 5% took over 6 years to achieve this growth.  Breast cancer tumor growth estimated through mammography screening data

The following research study found that "the median doubling time for invasive breast cancer is approximately 130 days" (considerably less than the 1.7 years from the previous study, but still more than 4 months).  They further found that the "the mean sojourn time is approximately 20 months", sojourn time being "the time that it takes the cancer to grow from a size at which it becomes detectable by screening to a size detectable clinically". Estimates of Breast Cancer Growth Rate and Sojourn Time from Screening Database Information

Based on this, it is unlikely (but not impossible, of course) for a lump the size of the "tip of index finger" (as cgood75 described her lump) to show up over night.  A cancerous lump is highly unlikely to grow from being undetectable to that size in just a few days. On the other hand, a cyst could easily do that.

I am 45 years old and been on Hormone Replacement Therapy for 15 years. I noticed on Sunday that my breast was sore on the outer quadrant of the right breast. I had a mammo about 3-4 months ago and it was clear. The pain has decreased but the spot is still there. It feels solid but not hard and it is not floating but closer to the chest wall. I would say in between a mass and a lump. I have always heard that breast pain is not a symptom of cancer so I am not that worried, more curious. I got into my PCP yesterday and she has ordered an ultrasound but I probably get that scheduled until next week. No strong history of BC but being on HRT for 15 years prompted me to visit my PCP.

I am scheduled for an ultrasound and mammogram but it isn’t until July 31 which I find a bit long of a wait. My lump has decreased in size but its still there. I also noticed a sore spot in my high up in my armpit but maybe I am just being paranoid now.

Not as painful thankfully. Thanks for your reply Denise.