Hello, I'm a small animal veterinarian and also see avian patients.
How long has Polly had this growth?
Is the growth ulcerated or open?
6 years old is a fair age for a budgie, it's possible that the growth is cancerous
If the location of the growth is amenable to removal, your local veterinarian (or closest avian vet) might be able to remove the growth if it's causing him a problem.
Sometimes we elect to do pulse therapy antibiotics, to control secondary infection and keep the site healed.
Another thing which can be done is wrapping his perches in a soft bandage material, this can easily be changed to keep the perches clean and helps to cushion the site from abrasion.
Of course general diet is so important in birds - feeding a good pelleted diet such as Zupreem pellets, or even Harrisons veterinary diet, along with fresh fruits and veggies daily.
Ultimately for the growth I would schedule an exam with a local avian vet, or small animal vet who will see birds. They may elect to try and remove it, or possibly provide some antibiotics and pain control if necessary.
Seems like maybe you are having trouble with this chat format. I will switch to Q&A format…. you will still be able to respond to me with further questions/specifics