Affection cutanée possible inconnue ?

Hello,
For about 1-2 years now my 61 year old father has had a weird problem with his toes.
They’re extremely and unusually thick, discoloured(blackish-brown) and are deformed.
He got a fungus test about 2 weeks ago and the test came back completely clean, nothing came up on it and the doctor was completely dumbfounded, he said hes “never seen anything like it before”

He’s going in to see a skin specialist in August but I’d like to see if anyone thinks they know what it is

Any help would be appreciated, thanks

(sorry if this is the wrong fourm topic by the way)

Shoot, just noticed the skin and nails subtopic, sorry lol

Can you post a few photos

yup, he is out currently but I’ll post some pictures in a bit