Mysterious Hidden Journey

I posted a few weeks ago about a betta I ordered online that had a mysterious white growth on his side. Started off VERY small, and has continued to grow over the course of about 3 weeks. Today it seems to have "ruptured" ... almost like an abscess or wound that opened up. The breeder had no idea what it was, but it's not fungal or bacterial. Others have said its a cyst or tumor. Has anyone seen this before? Since it's opened up, it's smaller and tiny pieces are sort of falling off. There are some flappy/stringy pieces as he swims. So strange....but doesn't bother him. First pictures are from a week ago, last 6 are from today. Mysterious Hidden Journey

He's the happiest fish ever, VERY friendly and loves his black neon housemates, snail, and shrimpies. I just hope he continues to do well. He's part of a tank I set up for my work (animal hospital) but he's technically my fish. Still no name for him, he was white faced with black eyes and red lips, but that's changed a bit. He still has red lips though which I adore LOL. Anyone have name ideas for him too? I like very unique names.