I have never heard of that. Thanks!I think you have a shed form a stag or cactus buck. Contrary to popular thought bucks with messed up testosterone do shed there antlers and often regrow another set. Sheds from these buck do not have the normal button on the base. Often the base is hollow like the one you found. Yours is a very extreme example and it looks like and animal could have chewed on it a bit. It is also common for sheds from these bucks to has remnants of velvet too.
Nice looking antler.
Is this the shed thread or big tree thread?