Good morning, @vero210,
Lymphoproliferative disorders are a group of diseases characterized by the uncontrolled production of white blood cells called lymphocytes. They’re called Chronic (instead of acute) because they’re often ongoing but are generally slow to develop. Chronic lymphoproliferative disorders are a group of diseases involving T cells, B cells or natural killer (NK) cells which are all components of the white blood cell.

Clear as mud, right? If your mom has a chronic disorder of her Natural Killer cells that means it’s not aggressive but more of a sustained increase in mature natural killer cells for longer than 6 months without a clear cause.

I think this article gives fairly good and easier to understand information on proliferative diseases, how they’re diagnosed and potential treatments.
https://www.healthline.com/health/cancer/lymphoproliferative-disorder#overview
You’ll learn about what this means and what your mom’s potential treatment options are after her biopsy report is read. Sometimes these blood disorders are separated by only small nuances so it can take time to get a firm diagnosis. When you find out we’ll see if there are other members here with the same diagnosis so you can Connect with them. So let me know, ok?