What Causes A Small Lump On The Nape, Neck And Shoulder Stiffness?

I have a small lump on the back of my neck about twice the size of a large pea. I had my husband look at it and he said it had a good size hole in it. When he squeezed it only clear liquid came out. He said it did not resemble an ingrown hair or a pimple. I had noticed stiffening in my neck and shoulders prior to discovering the bump and this increased dramatically when he squeezed the bump. The stiffness and aching now reaches down to my fingers on the left side.