What is the lymphatic System? Just like the arterial and venous network, there is another network in the body called the lymphatic network. This network is a part of the body’s immune system. The lymphatic system or network is formed by lymph vessels and lymph nodes. This network is present throughout the entire body carrying a thin clear watery fluid called the lymph. This lymph diffuses out of the capillaries, bathes the entire body structures collecting fluid, waste material, and other things (like viruses and bacteria) that are in the body tissues. Lymph vessels carry lymph fluid to the lymph nodes which are present throughout the body. The lymph nodes work as filters for harmful substances. They contain immune cells that can help fight infection. In the same way cancer cells are also be carried to the lymph nodes where they continue to grow and spread. When there is an infection, chronic infection or cancer in the region that the lymph nodes drain they swell up and get enlarged. In an acute infection the lymph nodes may be painful. As the acute infection subsides the lymph nodes become smaller and may completely resolve. Occasionally they become smaller but may not entirely resolve. In the presence of chronic infection lymph nodes swelling may be persistent. There are several causes for a chronic infection causing enlarged lymph nodes. The lymph nodes also enlarge when there is a cancer in the region. The cancer cells are carried to the lymph nodes whereby they continue to grow and may spread to other lymph nodes in the region. Sometimes, cancer may originate in the lymph nodes itself. Such cancers are called lymphomas. Cervical lymph nodes (Lymph nodes in the neck) There are several groups of lymph nodes in the neck draining particular regions of the head and neck. Depending on the location of the group lymph nodes in the neck, and for a descriptive purpose, the neck has been divided into six levels. Level I: Located just below the jaw the lymph nodes in this region drain the front part of the face, floor of the mouth and front part of the mouth (oral cavity). Level II: The parotid gland, the back part of the nose (nasopharynx) and the back part of the tongue drain into the lymph nodes located in the upper third of the neck. Level III and IV: The middle and lower part of the throat and the larynx (voice box) drain into the middle or lower part of the neck. Level V: Lymph nodes in this region drain the scalp and are involved in chronic infections. Level VI: This level drains the thyroid gland and the oesophagus. Enlarged or swollen lymph nodes in the neck are suggestive of a disease process in the region that drains into the group lymph nodes. If no pathology or disease is detected then it is likely that the disease process arose from the lymph nodes itself. When a patient presents with a lymph node swelling in the neck, the ENT doctor will do the following:
- A complete comprehensive examination. This will include palpating the neck to assess the size and consistent of the lymph nodes. Painful lymph nodes indicate an infective process though there can be exceptions. Painless, firm and rubbery lymph nodes may be indicative of a cancerous process. Examination will include f the oral cavity, salivary glands, tongue and the tonsils.
- A nasal endoscopy (rigid and/or flexible) will be done to examine the nose, nasopharynx, lower part of the throat back part of the tongue and the larynx.
- Further investigations will depend on the clinical findings and may include a biopsy if a lesion is identified.
- If the no cancer is identified, a fine needle aspiration of the lymph node may be done.
- Imaging studies like a CT scan or the MRI may be necessary.
There are several causes of enlargement of lymph nodes of the neck.
Some of the common causes are:
Acute Tonsillitis / Peritonsillar Abscess
Acute Suppurative Lymphadenitis
Chronic Infection of the lymph Nodes:
Tuberculosis of the lymph nodes
Cat Scratch Fever
Cancer of the throat
Laryngeal Cancers (Voice box)
Cancers of the Lymph Nodes: