Flipperflap,
I also was diagnosed with Melanoma, but have since successfully renewed my TC medical. I was diagnosed with MM, secondary site, unknown primary site, in Jul 2002. After the surgery, and follow up tests: head MRI, abdominal CT scans, lung xrays and blood tests, there was no sign of any mets, thus I didn't do any other follow-on treatments. I was in the Canadian Forces at the time, and their Doctors grounded me for about 18 months, pending the results of the above mentioned tests.
I applied for my TC medical in the Spring of 2006 (4 years after diagnosis). After my doctor forwarded copious amounts of medical paperwork, I received my Class 1 medical without any restrictions. I have since left the Air Force and fly offshore helicopters with CHC Global.
I'm very healthy and fit (proud Ironman Canada finisher 2006) with no evidence of disease.
I think both the FAA and CAA have procedures in place for approving medicals after a melanoma diagnosis, as long as specific diagnostic tests are completed. I believe the details can be found if you dig around their websites. That might give you some more ammo for TC.
All the best,
Triguy