My husband is getting ready to have his top surgery, but we have run into an issue. We don't know what tell his employer. We need to come up with another surgical procedure that is plausible so they wont ask questions. Any ideas??

Removing a large growth on his chest seems like a non-specific explanation that doesn't involve a lie.

I don't think you need to tell him anything, legally.  If he wants proof provide a doctors letter

Pectus excavatum.

Fixing a torsal structural abnormality from a birth defect?
Though, I love Sharky's suggestion too.

Or if he is comfortable telling a fib, he could bring up a family history with very prevalent breast cancer and is having his breasts removed as a preventative measure.
That's going to be the excuse I use in the future. >.>

Legally he does not have to give a reason for his FML ... he only has to have a doctors letter stating he is having a medical procedure and will be unable to work for x amount of time.

Hi. I recently ran into this problem myself, and was thinking about making up some other surgery as an excuse. After thinking about it, Lying to your employer could lead to being fired if they were to find out. Basically they cant ask you why you are getting surgery. I told my boss i needed a month of (IN OUR BUSY SEASON) for surgery and he said alright and never asked what it was for. If anything my regional manager asked if it was something serious, but never got any more into it then that. Good luck

I'm just going to say that they found some polyps in my chest and they need to be removed. Not technically a lie

No idea how I'm going to explain going abroad for it though!

When I was about twenty-two, I had to take a day off work to get an abortion. I told my boss it was for "minor surgery." The explanation was accepted without my needing to provide documentation; after all, it was only one day. But when I came back to work the next week, my immediate superiors and coworkers wanted more details. I told them that I had had a growth removed. It was a perfectly accurate description that didn't make me feel like a liar. Could your husband use such terminology?

(Of course, then there was the nosy little...person...who wasn't satisfied with the level of detail and wanted to know where the growth was. Some people...)

His co-workers and friends are going to want to know what's up. Being secretive will only fuel a fire that doesn't need to even start. We are looking for a legitimate surgical procedure that he could say he was having. The clinic that is referring him for surgery it no help, they all firmly believe he should be "out", and that is just not happening.

I would just say he had a benign growth then. 

The trick is to tell as much of the truth as you can without giving away the whole shebang.
Benign growths/tumors/cysts on his chest.
Or just plain gynecomastia surgery. He's been sensitive about it for a couple of years and finally decided to have something done. Lots of cis guys do.

The people at the clinic sound like asses, by the way. It's not their damned decision whether your husband is out. Sheesh.

I recently had top surgery and was terrified of telling my employer. I told my supervisor that I needed time off for surgery and he said "okay that's fine" completely relieved that he didn't ask what for. Then when I passed him the doctor's note he said "just give that to the nurse and she takes care of recording that stuff". That's when I almost sh** myself. I didn't know what to say. I wasn't about to lie to the work nurse. When I saw her I gave her the note and she asked what it was for. I hesitated and said "getting fluid drained" and she was like "okay, like from your lungs?" then I said "no... uh, my chest" Then she stopped and looked up at me then said "okay so chest surgery". Hahah ahh I was terrified.

I'm more scared of going back to work though. Co-workers are asking which hospital in Toronto I had to go to but I went to a cosmetic clinic in Mississauga.

When other co-workers ask I still just say "getting fluid drained" and some say "oh stuff from your lungs" and I just say "something like that, gotta wear drains for a while to get it all out after surgery" (I didn't actually need drains but some surgeons require it for top surgery, and for lung surgery) because they aren't my boss or the nurse. Surgery for that will leave people with scars kind of similar to top surgery. It sort of worked out because in a previous surgery one of my lung collapsed for no reason and had to open up the lobes. If that happens apparently you have a risk of getting sick and if you do fluid can fill in your lungs. Anyway, I've told people that story when I say I am nervous about it, that way it kind of is left to their own interpretation.