When a cyst is removed (from back) and it is sent for lab tests, what are the things they are testing for, is it just cancer or other things?

Microscopy test: Cysts mostly are not cancerous but benign. The gold standard test is histopathologic examination by a dermatopathologist or general surgical pathologist. In that "test", trained experienced doctors make a diagnosis, and usually does not need additional esoteric tests, unless suspected of atypical indeterminate pathology, which can range from benign to carcer.These are all done by microscopy.

They are: examining the tissue for a diagnosis, tumors being only a small percentage of cysts in the soft tissues of the back! The most common are sebaceous cysts. See attached! Hope this helps..Good Luck Dr Z