Hi, all lymph nodes including, cervical lymph nodes swell when infection occurs. white blood cells acts as a police, and lymph nodes acts as a police station. When infection present in that area, loading of bacteria occurs into lymph node so it swells up. Here your cervical lymph nodes are swollen it may be due to infection of your ear or throat. Yours montoux test is also positive, TB lymphadinitis may be the another possibility. Consult general physician along with your old reports for furthur evaluation and treatment.