What else could it be other than dupuytren?

4,5 years ago, i realized i had this small lump in my hand, went to the doctor (hand specialist) who confirmed it to be dupuytren after an ultrasound.

However i went to a hand surgeon for an unrelated matter and asked him for an opinion. He said it was weird that after nearly 5 years the mobility in my small finger was still impacted.

So what else could it be?

I am 27, so i was only just 23 when i got it, which is also unusually young.

I have also been climbing for 4 years at that point but all the doctors said that this was likely not the cause. I continue for a bit but usually had a feeling of a strain in my hand afterwards, so i still stopped.