1cm node in lower right part of neck for over a year now. us showed normal reactive node and doc said no biopsy necessary. why is node still here tho? no symptoms, has not grown, has gotten a lil smaller, mobile and oval shape

Lymph nodes . . .: filter tissue fluid/lymph fluid and if there is infection, it enlarges to produce lymphocytes which fight infection. When infection resolves , it shrinks, but depending on the original insult and size of node, there is extra framework that doesn't disappear right away. Also, ongoing URI and post nasal drip from allergies, etc. may keep it stimulated. Mobility, smaller size, no pain reassure.