Answer to Question 1
ANS: D
When immature bone marrow cells are seen in the CSF, it most likely means that bone marrow contamination of the specimen has occurred. If a significant number exist, then the CSF differential will be a reflection of what is in the marrow, not the CSF.
Answer to Question 2
ANS: A
Ependymal cells, along with choroids plexus cells, are lining cells of the central nervous system and are seen in CSF. None of the other findings would be normal in CSF.