The presence of blast cells in cerebrospinal fluid (CSF) can indicate central nervous system involvement in cases of acute leukemia. However, contamination of blast cells from peripheral blood is also possible if there is a traumatic tap.
Appearance
Blast cells in body fluid appear similar to those that may be seen in peripheral blood.
Cytocentrifugation may exaggerate cellular features, such as larger nucleoli or irregular nuclear shape. Chromatin is fine with one or more nucleoli.
Lookalikes
Lymphocytes may appear larger due to cytocentrifugation which can be mistaken for blasts if not careful. Patient history can aid in identification.
