Today we'll be looking into benign & malignant tumors. I'm sure most of you realize that a benign tumor is a "good" thing, whereas a malignant tumor is bad. But why? And more importantly, how can you tell them apart?
First off, what is a tumor exactly? More correctly called a neoplasm, it is basically a "new growth" - i.e. something grew that wasn't supposed to be there. This abnormal lump of tissue usually grows faster than normal tissue & cannot be regulated or stopped in the same way normal tissues are.
So how did the tumor get there in the first place? Genetic mutations. All it takes is one mistake in a key gene & all hell breaks loose - though usually it's more like a few mistakes in a few key genes. It starts with a single cell. All cells are directed by their DNA, safely housed in the nucleus. But various chemicals, radiation, etc can damage the DNA - this often kills a cell, but it sometimes leads to something new. A cell that can grow beyond all stop signals & quickly forms a tumor.
Alright, so there's a tumor. How do you know if it's benign? Generally, a benign tumor is very small & relatively innocent - it won't spread to other parts of the body & grows fairly slowly. The tumor is also a well-defined mass & easily removed surgically. Malignant tumors on the other hand grow very quickly & are likely to spread (metastasize). They are more difficult to remove too - they often infiltrate the normal tissues they're growing in & have less defined structures.
A biopsy of a tumor is often taken because the cells of the tumors look different too: a benign tumor has cells that look similar to normal cells, growing in a similar orientation. Malignant cells on the other hand are atypical - they look odd & sort of jumbled together instead of nicely stacked or lined up.