Why is my snuggly kitten occasionally ridiculously aggressive?

My girlfriend and I have a 10 month old neutered male kitten. He has always been the snuggliest lap cat either of us have ever met. He sleeps with/on us every night. He is our only pet. He is very needy emotionally and basically wants to be around us whenever we're home. He's still a kitten that has a bit of energy and wants to play frequently. We've purchased him a cat tree and countless toys and scratching posts. We play (vigorous chasing of a toy) with him for 10 minutes in the morning, 10 minutes when we get home from work, and 10 minutes before we go to sleep. 10 minutes seems to be as much as he wants to play at one time. Basically the rest of the time we're home with him, he snuggles.

He was always a very loving, gentle cat. Previously, when he would chase and play with our hands, he would never actually bite, but rather lick, and would never distend his claws. Something changed within the past 2 months, however, and it has gotten extreme in the recent weeks. Now, he'll just be laying on one of our laps relaxing and we'll be petting him and all of the sudden, he will grab and bite our arms. It is not a playful bite/nip. It is a full-fledged mauling. He is biting as hard as he can possibly bite and definitely breaks skin. He pins his ears back and his eyes are wide open. I've learned to noticed when he's about to do these things and just pull my arm away before it happens, but he will attack anyway. When he does attack, I will push him off my arm, but he will continue to jump back and attack.

I'm not sure what is causing this nor what to do. He has never listened to anything we ever say to him and he couldn't care less if he's sprayed with water. We've purchased numerous acrid sprays which are supposed to deter cats from various things, but he didn't mind any of them. We've never given a cat as much attention as we give him so it's hard for us to imagine that he's acting out becuase he's feels bored or neglected. Plus he acts out most often after he's been laying on our laps being pet for an extended period of time. I've had other male cats before who will give you a warning bite if you're petting them and they decide they don't want to be pet how you're petting them. But his are all-out attacks and he doesn't stop if you try to leave the area.

I don't know of any event that has occurred to explain this behavior except for him getting older. If this is just an adolescent thing that he'll grow out of, a surge of hormones as he becomes an , we'd just like to know that. If he could have some sort of chemical imbalance or is, in fact, acting out because of something, we'd definitely like to know about that.

Thanks in advance