What is a normal size [mm] lymph nodes in the mediastinum bilateral hilum? i have the sizes of mine, but not sure how large mine are in comparison.

Varies: Lymph nodes vary in sizes with each person and may be bigger in others due to their personal exposures. They can be anywhere from a few mm's to cms. What's more important is change in size and underlying abnormality.

Size not important: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.