What does swollen lymph node in the neck feels like? how common is swollen lymph node in the neck without any lump?

Always a lump: The lymph nodes in the neck as in other areas like arm pit and groin serve to protect the patient immunologically from infection. Tumors in the region of these nodes spread to the nodes and cause them to enlarge and become firm. Infections that induce somewhat larger than normal lymph glands do not develop the firmness. If tumor arises denovo in the nodes think of lymphoma.