The lymph nodes are composed of lymphatic tissue and are observed throughout the human body, mainly in the neck and the underarm. In the event the lymph nodes in the neck have been infected, the individual will have the ability to feel a difficult mass right at the rear of the neck. Most often, they may not be serious. Your posterior cervical lymph nodes can be found close to the rear of your neck. Swollen lymph nodes are frequently the very first indication of lymphoma. Therefore, if you become aware of a swollen lymph node for an elongated time period, you should speak to your health care provider.