Comet with weird bumps

[cnyguy]

14 year old comet with 2 bumps that "erupt" every few weeks. Any advise would be helpful and welcomed! I've attached photos. Need to get this treated soon but not sure what to do. Thank you!

 

[Aiken Drum]

Are they falling off and regrowing or receding and re-emerging?

 

[cnyguy]

Receding and reemerging.

 

[cnyguy]

Seems like a parasite but not sure which type of why. It is the only fish in the tank!