How do you make sense of histology report?!

My pathology report arrived in the post this morning care of my very helpful surgeon. Now I am just trying to make sense of it before my meeting with oncologist this afternoon to discuss my treatment plan, especially as I’ve been told I am borderline for chemo.

Does anyone know what this means: Grade 3 (T3 P3 M2)? I know the grade 3 bit refers to how invasive/aggressive the tumour is but what do the other letters and numbers mean?!



Hi Jackie,
If you look on the main webside they have a helpful leaflet called ‘understanding your pathology report’ which you can download for free. As far as I recall it explains these letters and what they mean.

Hope all goes well with your oncology appointment and that you have a clear plan at the end of it.

Edit - just checked it, it doesn’t give them however MacMillan site does explain the TNM staging system. I have seen posts on here that explain so I’ll have a hunt for you.

Thanks for such a speedy response Revcat! Yes, I already have that document but it doesnt appear to explain the T3 P3 M2 bit though! Not sure where to find that info…?!

Hi Jacqui,

It’s alot of jargon isn’t it? But you’ll be an expert in no time at all (unfortunately!).

Yes - grade 3 means how quickly it grows (I had a second opinion with a lovely oncologist who said he hated the word aggressive as it is so negative). Good news is that grade 3 usually responds the best to chemo.

T3 means the tumour is more than 5cm.

Ummmm…are the other letters and numbers right? Never heard of P (unless it was P+++?) and they usually include N for lymph nodes and M is either MX, M0 or M1?

Hmmmm…maybe give the helpkine a ring? There are lovely breast care nurses on the other end who will be able to take you through it.


Just read your old posts. Your tumour was only 12mm - so the T bit seems weird too…???

They usually use TNM as on this link:

Hi Sandytoes - yes it is a bit odd! I don’t think it refers to staging but to the grade - I remember the surgeon saying something about the mitoses which I think is something to do with cell division of the tumour…I guess all shall be revealed this afternoon - or at least i hope so! Thanks for your help.

Hi Jackie,
sorry, despite a search I couldn’t find what I was hunting for on here. I vaguely recall that there is a system where some of the letters relate to how they found things out - so radiography, ultrasound, pathology etc. and i thought it was LuLu43 who had posted it.

Hope it goes well for you and that you have a clear plan of what next.

Meantime avoid the temptation to google cos there’s lots of twaddle out there.

From what I remember they look at the cell for 3 different thing and scale it from 1 to 3, I remember one was mitoses but can’t remember what the other 2 were. It’s a visual look so I can be interpreted slightly differntly by different people on different days. Its just a guide for the tratment plan. I got 3+3+2 and got grade 3

You’ll get a better explanation this afternoon.

Best wishes


Hi Jaqui

I asked my son the exact same question and this is the answer I received

"P3 T3 M2 are codes for characteristics of the cells under a microscope (nuclear Pleomorphism/Tubule formation/Mitotic count)these numbers add up to give a score that corresponds to the “grade” of the cells.

Hope that helps

PS My son is a medical doctor and spent a fair bit of time peering through said microscope.

TNM is used to describe the STAGE of cancer.

T stands for tumour
N for node involvement
M for metastases

However, the GRADE is defined on by using TPN.

Tubule Formation = T
Nuclear Pleomorphism = P
Mitosis Count = M

That’s about the description of the cells and how much they look different to normal body cells.

Each category is scored 1, 2 or 3.

Tubule Formation (% of Carcinoma composed of tubular structures like a normal cell)
> 75% 1
10-75% 2
less than 10% 3

Nuclear Pleomorphism (Change in cells)
Small, uniform cells 1
Moderate increase in size and variation 2
Marked variation 3

Mitosis Count (Cell division)
Up to 7 1
8 to 14 2
15 or more 3

If you score 8 or 9 you are classed as Grade 3.

If you score 3 in the first 2 categories and 2 in the last category, your total is 8 which is Grade 3.

I found out my TPN on Friday. I scored 3 in the first two categories and 1 in the last category and my score was 7 which is Grade 2. My score is provisional because it is only from the biopsy; my full result will come after the surgery so my score may change then.


Still not asked for mine. Head…sand…

‘head… sand…’ not necessarily. Not everyone wants or needs to know.

My lot just told me stage, grade and nodes and didn’t offer me the full report. I know well enough what all that implies… and that’s enough for me thanks all the same.

elttiks, I confused the TPM with TNM at first and just saw M=1 and freaked quietly until I saw “Grade 2”…

That’s all I have seen; no full report until the tumour is out. I only have a biopsy to go on

Which of course is why google is so dangerous.

It would help if they could come up with some different letters though… doesn’t take much to put the mind into freefall

My words seemed to compute. Breast. Nodes. Neck. Chest wall. Grade3. Stage3. ER+. That was enough info for me.