He apparently had been hiding it under a ten-gallon hat, for how long I'm not sure. Seems like that would take a while to grow but from what I've read about amelanotic nodular melanomas - which is my best guess about what that is - they can develop rapidly.
Recently got in touch with another ex-pat I used to hang out with there, that's who took (and sent us) the picture. Once he got a peek at what was under the hat he said: "Pat, get in the car" and they were off to make the 700 mile drive north to San Antonio fairly immediately.
I guess they didn't do much at the VA hospital there, looked at Pat like he was from the moon. Maybe too large to cut off, I dunno.