Okay. Anyone who has read Concrete Jungle in both comic and Novel form is sure to have been caught off guard by the extreme changes between them. I know I have, I read the novel first and got the comic thinking it was going to be like the book, boy was I confused.
In fact: All the A,P, and AVP Books under the Bantam banner have some extreme differences from the comics of origin (the best example being the "Wilks and Billie" salvaging of the first 3 novels after Alien 3 ruined a few good comics for us.)
Feel free to put in any that I miss.
1. The first attack at the abandoned apartment: In the comic, most of the bodies are splattered about the floor while a few are skinned and hung. In the novel, they're all skinned and there are a few more bodies found on the roof.
2. The second attack: In the comic, it's in a subway filled with corporate cowboys. The attack is a confusing one, because the Predator attacks a subway full of non-aggressive commuters (unlike Predator 2 where everyone was waving them around). In the novel, the attack takes place at the Police Firing range, probably meant to make it personal for Schaefer. Also introduces the character of the Police officer who later helps Rasche obtain the illegal weaponry.
3. Schaefer meets The Predator: In both versions the fight is pretty much the same. But the novel makes the survival of his falling out the hole on the FIFTH FLOOR of an apartment slightly more easier to swallow (He lands on a makeshift crash pad made of garbage bags, unlike in the comics where his fall is barely interrupted by clothes lines!).
4. What Rasche was doing while Schaefer was in South America: In the Novel, we have a moment where Rashe tries to flee New York, but goes back when some of Philips' goons are following him.
5. The Dead Predator and Attack 3: In the Comics, the Predators just magically know about the Predator that Schaefer killed. In the Novel, we get a scene where an Army Retrieval team is slaughtered by a group of Predators who just found and/or are in the process of collecting their fallen comrade (This also eliminates any possbility of a "Dark River" novel in the process, but I doubt that would've been written anyway.)
6. Additional Attacks: In the Novel, we are treated to a sequence of events in New York that tell us that the Predators have been slowly picking off members of Carr's gang.
7. Eschevera: In the comics, this subplot just kinda hops in and is quickly eliminated just to show that the Predators are pissed during the subsequent attack on the Columbian Cartel Camp. But in the novel, we are treated to an assortment of foreshadowing moments.
8. Rasche captured by goons: In the comics, he was kidnapped by the I.R.S. (which was pretty damn funny when I read the "Oh my god....Accountants!" bit). In the novel they were average MIB's.
9. The Fifth Avenue Rumble: The Novel gives Schaefer, Rasche, and Carr a few more gang members as backup. And we get some slight changes to the build-up to the ground conflict after the Predator ship decloaks and lets loose. ("Oh god....and on a SALE DAY!") But it's pretty much the same unless I blanked out while reading.
Well, those are all the pretty obvious ones apart from the Character Development scenes which were unnecessary to list down because they actually aide the story and not change it. Anyone who's more eagle-eyed than me is free to join in.