Non-specific esterase
When you’re faced with an acute leukemia composed entirely of blasts, one way to figure out the identity of those blasts is to use cytochemical stains. These stains are applied to slides – either smears (blood or bone marrow) or sections (of bone marrow) – and are read under the microscope. There are several different cytochemical stains that are commonly used in hematopathology, one of which is the non-specific esterase (or NSE) stain. Monocytes and their precursors (promonoblasts and monoblasts) stain a pretty red color with this stain. Neutrophils and their precursors (including myeloblasts), and all the other types of cells in the bone marrow, for that matter, are negative.
So if you have a leukemia composed of a sea of undifferentiated blasts, you could stain the blood or marrow smears (or the bone marrow section, though it’s harder to see individual cell morphology on a section) with NSE. If the cells stain red, then you’re dealing with a leukemia composed of monocytic cells – probably a monoblastic leukemia, if all you’re seeing is blasts. It’s a quick and easy way to help you diagnose the leukemia.
August 5th, 2009 at 9:34 am
In this micrograph, many NSE stained cells have segmented nuclears, they are looks like more close to mature neutrophils. Do they truely belong to monocytes?
August 5th, 2009 at 10:21 am
Yes – many of the NSE positive cells in this slide do appear to have somewhat segmented nuclei. However, they are actually monocytes (NSE only stains monocytic cells, not neutrophilic cells) – it’s just that the nuclei have a somewhat lobated appearance in this particular preparation. Cellular details are not as clear in cytochemical stains as they are in regular Wright-Giemsa stains, so when you look at NSE and MPO stains you need to keep that in mind and allow for a bit more variation in morphology.
August 6th, 2009 at 10:03 am
Very useful explaination! Thank you, and I do like you to teach pathology like this way. Keep going!