Terry Wright, 60, started losing his hair and beard ten years ago.
Since then, the father of five has developed smooth skin, hot flushes and breasts.
Mr Wright, a pub singer from Birmingham, gets harassed by local children who call him the "She-Man".
"I get mocked by kids where I live who call me She-Man and other names. Once a child bumped into me and its mother said, 'Say sorry to the lady.'
"My mates are shocked at my appearance but try to make light of it by saying I'm just a pretty-looking man," he said.
Mr Wright, who has to wear a wig, has a slim build and is 5ft 4in height, making him appear even more feminine.
Blood tests have revealed that Mr Wright has abnormally high levels of the female hormone oestrogen. But doctors who have examined him say they have never seen such a case – and do not know what to do to reverse the process.
Some testicular cancers can produce high levels of oestrogen and drugs that used to treat prostate cancer can have similar effects. However, doctors say this in not true in this case.
An MRI scan has ruled out the oestrogen surge being caused by a tumour and a psychiatrist has judged him mentally sound.
His GP wrongly suspected he was trying to change gender and offered him a sex swap which he refused.
"I am a man, not a woman. And I do not want to be a woman. I just want to get my life back to normal," he said.
Professor Richard Ross, a hormones specialist and the head of Endocrinology at The University of Sheffield said: "This case seems very unusual."
Mr Wright added: "Doctors call me an 'interesting case' and 'unique' but I just want to go back to being a proper man."
