Aquariums: Is this a parasite? Or wound/tumor

My betta was fine 2 days ago and last night I got home from work and saw this

Tank – 7.1 gal rimless tank

Substrate – fluval stratum

Heater and Filter (Aquaclear)

Temperature – 78-80f

Ammonia – 0

Nitrites – 0

Nitrates – 0

Ph 7.4

I've had the tank set up for about a year now and the betta has been in there for about 6 months

Water changes approx 1x month (25%)

Tankmates – 2 Mystery snails and about 20 neocaridina shrimp

Food – hikari vibra bites 7-10 pellets 6 days a week

Decorations – driftwood