Ant-Man/Giant-Man: Growing Pains written by Stan Lee, Steve Englehart, George Perez, and Christos Gage with art by Jack Kirby, Don Heck, George Tuska, Jeff Moore, and Tom Raney
This anthology of stories focuses on Hank Pym, the scientist who discovered Pym Particles and was the original Ant-Man. The first story reintroduces him as Giant-Man--he uses the particles to make himself bigger rather than smaller! In the second story, he renames himself Goliath. In the third story he's going by the moniker Yellow Jacket. In the fourth and fifth stories, he's back to being Giant-Man (with occasional moments of being ant-sized if not Ant-Man).
In case you didn't deduct it, Hank Pym is both a brilliant scientist and a man suffering from a massive insecurity complex. So he has to fight both super-villians and his own feelings of inadequacy and self-doubt--often at the same time. The balancing of the two is hard to do from a story-telling perspective. The fourth story is the longest (a four-parter, the rest are single stories) and most successful at telling a story that combines outer conflict and inner conflict. Hank is working with a partner to use a variant of Pym Particles to end world hunger. Some side-effects cause monstrous insects to appear and various other characters exposed to Pym Particles (like The Wasp and second Ant-Man Scott Lang) to have serious difficulties with their powers. The overall problem is labyrinthine and eventually Hank Pym figures it out, but not until he's gone through a lot (including a stint in a straight-jacket).
Mildly recommended-the book is interesting but full of hits and misses.