Is this fungus?
 

Hi everyone,
Just bought some orchids online. I was so excited about getting home today because they were delivered. Well when I got home and opened the package I found 2 vandas and a cattleya. Well my cattleya looks like it might have some fungus. I took some pictures and would like to know if it is fungus. If so, can I cut off this one leaf leaving the bottom piece?
Thanks for any advice.

It doesn't look like fungus to me but the picture isn't too good on my screen. Could be a mold or mechanical damage. Can you rub it off? If it isn't spreading then no problem. Until you decide, keep it away from any other orchids you have. The spots and markings don't have a solid edge to them from my picture. If it were rot it would have a distinct edge and the dark tissue would be soft. Nice new growth there. I would repot this in a good bark/sponge rock/charcol mix. That new growth should have some nice new roots. Just be careful and not damage the new roots. After bleaching the pot, put the orchid right back into it.

Just giving this a bump so I can follow the answers.

I was looking around on the site here and it looks like it could be brown rot. I will try to rub it off. I will try to clean it with some peroxide and let you know what, if anything, happens.

I got a cattleya that looked similar and I took a felt pen and circled the area. That way I could keep track of whether it expanded or stayed the same. I treated mine with some peroxide and it never got worse. Don't know what it was but it didn't seem to affect anything.