I as well have been diagnose with a positive N-type antibody. I had the test done twice and came back positive both times. My Neuro did EMG checking for Lambert eaton he says they were negative .So he schedule a ct of the chest. Turns out a 6mm nodule was found in the right lower lobe of the lung. Pulmonolist wont say its cancer till he sees if it grows. So now its the waiting game.