Tiny lump on thumb

[Mummabear10032021]

Anyone know what this could be? It's been slow growing for years. I know it's still tiny but lately it big enough to be catching in things and it's sore.
It's shiny and firm

It might be a ganglion cyst. They can grow on the palm side of the hand (among other places) at the joint. I’d send some photos to an e-consult.