Because sometimes it is difficult to differentiate between WBC and
mesothelial cells, our policy is to count all cellular elements as WBC and
include them in the mononuclear category. Not monocytes but mononuclear
category which includes monocytes, histiocytes, mesothelial and epithelial
in the case of BAL fluids. All tumor cells are classified as "unclassified"
catagory. We also have a policy of having all body fluids reviewed by the
pathologist for comments. Most of the time they comment "Reviewed and agree"
with their name on it. They can thus bill for that service for revenue.