Enlarged posterior lymph node (~1.0 cm) for over six months. lymph node has not changed at all. no other symptoms. should i seek more tests?

Full examination: A single 1 cm lymph node in the neck that doesn't change over 6 months isn't likely to be a serious problem, but it is worth having it looked at to see if there is a source or explanation for it. Is the node soft, rubbery, rock hard? Is it freely mobile or bound in place? Is there anything in the mouth or head that might explain it? If it is worrisome, a biopsy would give the best answer.

If worried see MD: In most things medical stability suggests benign. 1cm is usually a benign size cutoff for nodes(but larger are still frequently benign). Lack of associated symptoms is good too. Nodes usually swell related to some inflam process. When this ends the node goes down. Sometimes it stays large anyway. It's like a party and the last one out is supposed to turn off the lights. Partys over but lights on.