Hi,my 4 year old son has a lymph node in his neck which measures 1.1 cm by 0.4 cm,it has no visible hilum,but has an oval shape and shows vessel supply in color doppler which makes the doc think hilum is there.he is a healthy active boy with no symto?

Odd post: The hilum is just the physical structure noting where the lymph vessels enter the structure. The description you cite sounds like a normal lymph node. It seems either you or the doc are using the term in a way that has created some confusion. I see no reason for concern over the findings presented.

Watch and wait: You may feel the node every couple of weeks, if the lymph gland doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or your son develop fever, or loses weight, you should see a doctor. Wish you and your son good health!