Brown raised bumps on Cattleya leaves

[ocean217]

Can anyone help me diagnose this problem? Please!
These raised bumps do not scrape off. When looking at them with a microscope, I do not see anything that looks like scale or insects. When probing the center, there is definitely healthy tissue. It is spreading though. When emptying the bark on a piece of paper, I see no signs of insects, fungus, etc.
Thanks for any help you can offer