Small bean sized palpable moveable posterior cervical node for 5+ weeks. found tooth abscess and had root canal 2 weeks ago with antibiotics. off antibiotics for 1 week node not reduced. no other palpable nodes or symptoms. should i do something else?

Would check with your ENT physician...may be inflammatory but needle aspiration biopsy or node biopsy may be needed if node is persistent.

Since you know the reason for the presence of the posterior cervical node enlargement there is no concern for malignancy. I would give this several months for resolution.

2 possibilities. 1) You have an infection elsewhere that has not been uncovered, or 2) node has not had enough time to return to normal or node has been permanently altered. Report your concerns to thee Dentist or specialist Endodontist that did your root canal treatment. He/she is responsible for your post-procedure care.

You can watch and wait. You may feel the nodes every couple of weeks, if any of the lymph glands doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or you develop fever, or lose weight, you should see a doctor. Wish you good health!