Welcome to neoplasia. What does that mean to you? Proliferation of cells.
It means that a cell is going to remain within a cell cycle for a long period of time
and depending as to its behavior, it may then go on to be more benign in nature or malignant.
By the time we're done with the particular section,
you will have then become an expert in the basics of neoplasia.
Neoplasia, new growth, not reversible is a key, even with benign.
Remember, if a cell undergoes increased mitotic rate, at some point in time within that cell cycle,
meaning to say, that you're in the M phase, very difficult to reverse that.
Dysplasia, a very important topic. For example, let's say that you have an organ, that's undergone hyperplasia.
In any point at time with hyperplasia which means increased number, right?
And one would think with hyperplasia that there might not be a tendency of going on to neoplasia.
That is incorrect.
For example, if there's endometrial hyperplasia that might be taking place in a patient who is above the age of 50,
a female, meaning to say post-menopausal and you start bleeding,
you see bleeding coming out a cervical os. You're kind of worried now, aren't you?
That there's possibility of endometrial hyperplasia and then, concerning of endometrial cancer.
But it's not like hyperplasia just went into cancer, right?
It has to go through a period of dysplasia.
So, put things into perspective.
Or for example, you've heard of HPV and you've heard of high-risk strains, 16, 18, 31, 33.
And you should be thinking about the cervix and with the cervix and in the developing country in the world,
cervical cancer is a pretty big deal. But before it went into cervical cancer,
what kind of changes did the cell of the cervix undergo?
CIN 1, CIN 2, CIN 3, Cervical Intraepithelial Neoplasia, we have to call this dysplasia.
So, dysplasia is not neoplasia as of yet but my goodness, is it close
and you as a clinician, you hear the term dysplasia,
you're absolutely worried about your patient going on to cancer.
A disordered growth which is reversible but unfortunately, may result in neoplasia as a rule of thumb
as far as you're concerned, even with the most severe or serious type of dysplasia in the cervix,
let's say CIN 3, with that high grade type of dysplasia,
it still would take approximately a decade for that dysplasia to go on to cancer. Keep that in mind.
Dysplasia is a very important topic for us. What is a tumor? A tumor is swelling.
In basics, with tumor hemodynamics, we talk about histamine causing tumor, how is that possible?
Histamine caused the vasodilation, therefore, bringing about enlargement.
In this case, with basic neoplasia, we're dealing with increased proliferation of cells.
Therefore, we have a tumor and the behavior of that tumor could be either benign or malignant and we will be spending time with that.
Now, before we move on though, the other point of demarcation here would be malignant and metastasis.
Just because you have a cancer or in neoplasia, that is malignant,
you're one step closer to perhaps metastasis but malignant doesn't always have to go into metastasis.
It's one step closer, so, you're definitely worried about that increased proliferation
and therefore, causing rupture or penetration through the basic membrane.
We'll talk further about this. And then, we have actual cancer.
Cancer would be malignant neoplasia.
For example, if you have renal cell carcinoma or colorectal cancer, so on and so forth,
and this type of cancer you're worried about the membrane then rupturing and therefore entering spread.
In other words, you've now gone on to the highway.
What I mean by that is you've ruptured the membrane, you've entered the highway
and that highway meaning to say, either the lymphatic or perhaps the hematogenous spread
and once that happens, then, my goodness, you're going to have spread that cancer, well, step by step, by step.
Regional lymph nodes, from the regional lymph node, it might then go onto further lymph node
and then, before you know it, there's widespread metastasis. How important is metastasis?
If you remember, oftentimes, the most common cancer within an organ is not primary,
it'd be metastasis from a primary.