i read (eons ago it seems) that there are several different types of tumors. the three most common:

cysts are almost like internal blisters (filled with liquid) they can come and go, and are generally harmless, (but more prone to infections--which can cause secondary problems.)

tumors, generally self contained hard nodules. they grow, and grow, but they are seperate. (sometimes they have a membrane or 'shell' but even when they don't, they are more like a foriegn body inside your body.)

Cancers are crab like--they have long thin arms that extend their reach, they 'burrow' into tissue, (instead of being a lump that is piggybacking on the tissue)

this is why cancer surgeons have 'cut extensively' to remove them.
When they discover a small cancer 'nodule' in the lung, they remove a whole lobe, or half the lung--because the nature of cancer is to have long thin crab like arms that extend far beyond the body(nodule) and if you don't remove all of it, the 'arm' will continue to grow.
(crabs can grow new appendages if one is broken off)

but i am sure the doctors on board will chime in with some technical terms!


my other obsession