I don't know if this has been talked about in the past but I've never understood why these surgeries are treated differently from other patients who want a healthy body part removed.
Here's an extract from a case a few years ago and look and how differently it reads from these cases of "gender reassignment" surgeries:
"Andrew Smith believed his left foot was not part of his body and, since the age of eight, had experienced a pathological desire to lose his left leg. This intensified over time and, as far as he was concerned, by the time he was an adult, amputation above the knee was the only option.
When Mr Smith sought professional help, he was prescribed electroconvulsive therapy (ECT) and a selective serotonin reuptake inhibitor, but neither improved the problem. After years of psychological evaluation, he was diagnosed with body dysmorphic disorder (BDD); this psychological condition, also known as dysmorphophobia, causes individuals to become preoccupied with an imagined or minor defect in their appearance to the extent that their social, occupational or other areas of functioning are impaired.
After years of searching, Mr Smith found a sympathetic surgeon with a particular interest in amputation surgery. Mr Jenkins was willing to amputate the healthy leg, believing the diagnosis of BDD to be incorrect. He felt people seeking amputation of healthy limbs may have one of four different conditions - self-mutilation, dependency, sexual gratification, or a desire to lose a limb that has become an all-consuming part of life. Mr Jenkins believed the last condition applied to Mr Smith; importantly, he would not consider surgery for people in the other groups.
...
After 18 months’ careful consideration, Mr Jenkins approached a private hospital where he hoped to carry out the amputation. Although the hospital’s medical advisory committee supported the surgeon, the managers did not, so he approached the medical director of an NHS trust who consented to the surgery taking place.
Mr Smith had his left leg amputated; he paid for the surgery and a five-day stay in hospital; Mr Jenkins waived his fee. The surgeon went on to carry out another “healthy limb” amputation at the same hospital, but when a third man requested such a procedure the trust’s new chief executive and chairman put a ban on the surgery and ordered an internal ethical inquiry."