CSF contaminated with peripheral blood from a traumatic tap or an SAH may have all the nucleated cell types seen in the patient's peripheral blood. Therefore, if abnormal or immature cells are in the peripheral blood, they can also be observed in the CSF.
Several types of blood cells are present on this slide from a patient who has suffered a cerebral hemorrhage. Lymphocytes, segmented neutrophils, and mature red cells can be easily identified.