Joce, I'm in the US so I'm not familiar with the procedures in the UK. I don't think a visit to the emergency center is necessary unless you have acute systems (servere pain, fever, etc) as I don't believe they will do a biopsy in the ER.

In my case, I went to my GP first, who referred me to an oral surgeon who did a biopsy in the office (on my second visit). When it was confirmed that I had cancer, I went to an ENT who did my surgeries.

I don't know how things work in the UK, but when I first called the ENT's office to make an appointment after I was told I had cancer, the "first" available appointment was weeks away. I made that call from the parking lot of the oral surgeon who just gave me the news I had cancer, so I went back into their office and they made the call to the ENT and I got an appointment with the ENT that week.