What would cause one cervical neck node to stay enlarged for 2 months? not hard or tender, its mobile and soft but wont go away. no symptoms. 1cm

depends on age: A single soft enlarged non tender lymph node indicates most of the times a benign condition secondary to an inflammation in the nearby draining terrain including skin or a tooth as indicated by the specific part of the neck . A more serious condition is considered when more lymph nodes ,specially if hard are felt particularly in persons over fifty.