stingray goiter or hematoma?

[peter ray]

Last night my sting ray developed this large bump on the right side / top of head....next to his eye. I heard him bang into the top of the glass the day before & thought he got a bump / hematoma injury. This morning he was still eating. Tonight when I was feeding I noticed the bump was much larger and extended to the underside. I have 2 pictures here. Is this a goiter or a hematoma?
Water parameters are normal. Salinity is also normal. I have had him over a year and a half with no problems what so ever. He is still trying to eat, but is having a problem opening his mouth. Can anyone help with what this could be? I don't want him to die or be in any pain. Medications?
Thank you.

 

[beth]

Peter, it seems unlikely that the bump comes from bumping the glass. Is it just a bump with no reddening or marks?
I'm going to copy your thread to the Aggressive Forum to see if hobbyists with specific exp. in rays can assist.

 

[peter ray]

:notsure: no reddening anywhere on top or bottom...........
no white lesions.............
no cuts................