My pet conure ( a kind of small parrot) just had a mass removale operation. The histology report indicated that the mass was a low grade hemangioma, a cancer of the blood vessels. it was in the skin, superficial to the muscles of his chest wall. It seems to be a rare condition, the histology report only prognosis information for dogs. Does anyone know of a bird with this tumor? Did the bird recover? My pet is recovering well from the operation, but I am having trouble finding information abou this.
As a fellow conure owner, I’m sorry to hear about your bird’s tumor. 
Avian medicine is still nowhere near as advanced as canine or feline medicine is. I doubt you’ll find much (if any) information in the literature about your bird’s tumor. It might even be the first low-grade hemangiosarcoma reported in a parrot. I think you’re going to have to extrapolate from the dog data (risky), and hope that the surgery successfully removed the tumor and it won’t reccur.
I hope your featherd buddy is feeling better soon!