Procedures: Cervical Lymphadenectomy (Neck Dissection)

Cervical lymphadenectomy, also called neck dissection, is an operation that removes lymph nodes from the neck, most often as part of the treatment of thyroid, mouth, throat, and skin cancers.

What is a neck dissection?

A cervical lymphadenectomy, more commonly called a neck dissection, is an operation to remove lymph nodes from the neck. It is most often done as part of cancer treatment, either to remove lymph nodes that already contain cancer or to remove nodes that are at high risk of containing hidden (microscopic) cancer.

What lymph nodes do. Lymph nodes are small, bean-shaped glands that are part of the body's immune and drainage (lymphatic) system. They act as filters, trapping bacteria, viruses, and other harmful material, and they house immune cells that help fight infection. Fluid called lymph drains through the tissues of the head and neck and passes through these nodes along a fairly predictable path. Because of this predictable drainage, cancers of the head and neck tend to spread to specific groups of neck nodes first. Removing those nodes can remove cancer that has spread and can also show how far the cancer has traveled. Additional background is available in the Learning Center section on lymphatics.

Why is a neck dissection performed?

A neck dissection is used in several situations:

• Thyroid cancer. Thyroid cancers, especially papillary thyroid cancer, commonly spread to lymph nodes in the central neck (around the windpipe and thyroid) and the sides of the neck. When nodes are known or strongly suspected to contain cancer, they are removed, often at the same time as removal of the thyroid gland (thyroidectomy).

• Oral cavity and throat cancers. Cancers of the mouth (tongue, floor of the mouth, gums), tonsils, base of tongue, voice box (larynx), and throat (pharynx) frequently spread to neck nodes. Background is available for oral tumors, oropharyngeal cancer, and throat tumors. Nodes may be removed because they are known to contain cancer, or removed preventively when the risk of hidden spread is high enough to warrant it (for example, based on how deeply a mouth tumor has grown).

• Skin cancers such as melanoma. Melanoma and some other skin cancers of the head, face, scalp, and neck can spread to nearby lymph nodes. When these nodes are involved, a neck dissection may be part of treatment. A smaller operation, sentinel node biopsy, is sometimes used to check whether nodes contain cancer.

• Other neck nodal disease. Sometimes cancer is found in a neck node but the original (primary) site is unknown, or other cancers involve the neck nodes. A neck dissection can be used to remove the disease and help identify where it came from. General information about neck masses is also available.

The lymph node levels of the neck

To describe exactly which nodes are being treated, surgeons divide the neck into numbered regions called "levels," from I to VI (and sometimes VII in the upper chest). Each level corresponds to a specific area:

• Level I - under the chin and jaw (submental and submandibular areas)

• Level II - upper neck, near the top of the large neck vein (upper jugular)

• Level III - middle of the neck along the jugular vein (mid-jugular)

• Level IV - lower neck along the jugular vein, above the collarbone (lower jugular)

• Level V - the back or side of the neck (posterior triangle)

• Level VI - the central neck, around the windpipe and thyroid gland

Different primary cancers tend to spread to different levels, so the levels chosen for surgery are matched to where the cancer is most likely to travel. More detail is available in the Learning Center section on the neck.

Types of neck dissection and how the type is chosen

There are three broad types of neck dissection. The main difference is how many node levels are removed and whether certain important non-lymphatic structures in the neck are preserved. Those key structures are a nerve that helps move the shoulder (the spinal accessory nerve), a large vein (the internal jugular vein), and a prominent neck muscle (the sternocleidomastoid muscle).

• Selective neck dissection. Only the specific node levels most at risk are removed, and the nerve, vein, and muscle are preserved. This is the most common and least extensive type, used when the risk of spread is limited or confined to certain levels.

• Modified radical neck dissection. All of the main node levels on one side of the neck (levels I-V) are removed, but at least one of the key structures (the nerve, vein, or muscle) is preserved. This is used for more extensive nodal disease while still trying to limit long-term effects.

• Radical neck dissection. All of levels I-V are removed along with the nerve, vein, and muscle. This most extensive procedure is now used less often because of its effect on shoulder function, and is generally reserved for advanced disease where cancer directly involves those structures.

How the type is chosen. The type is selected based on the location of the primary cancer, the size and number of involved nodes, whether cancer appears to extend beyond the nodes, and findings on imaging (such as CT, MRI, ultrasound, or PET-CT) and during surgery. In general, more limited (selective) surgery is used when disease is limited, and more extensive surgery is used when there is bulkier or more widespread nodal disease. The goal is to remove all of the cancer while preserving as much normal function as safely possible.

Before, during, and after surgery

Before surgery. The care team reviews imaging and biopsy results to plan which side(s) of the neck and which levels to address. Standard preparation includes blood tests, a review of medications (some blood thinners may need to be paused), and instructions not to eat or drink for a set period beforehand. Further preparation details are in the neck dissection surgery packet.

During surgery. A neck dissection is performed under general anesthesia, meaning the patient is fully asleep. The surgeon makes an incision in the neck, often placed within a natural skin crease to help the scar blend in. The targeted lymph node tissue is carefully removed while nerves, blood vessels, and other structures are identified and protected. One or more soft drains (thin tubes) are usually placed under the skin to collect fluid and help the tissues heal flat (see drain care). The incision is then closed in layers.

After surgery. Most patients recover in the hospital for a short stay, often one to a few nights depending on the extent of surgery and whether both sides of the neck were treated. The drains typically stay in for a few days until fluid output decreases, and are often removed before or shortly after going home. Pain is usually manageable with medication. When the central neck or thyroid area is involved, calcium levels may be monitored because nearby glands that control calcium can be temporarily affected.

Recovery and what to expect

Recovery varies with the extent of the operation. Common experiences include:

• Neck stiffness, swelling, and tightness that gradually improve

• Numbness of the skin of the neck, ear, or the area near the incision, which may be long-lasting

• Temporary difficulty turning the head or lifting the arm

• A scar that fades over months

Many people return to light activity within a few weeks, though full recovery of neck and shoulder motion can take longer and is helped by exercises. The care team provides specific guidance on wound care, activity, and diet (a low-fat diet is sometimes used temporarily to reduce the risk of a lymph fluid leak). A fuller timeline is available in recovery expectations after neck dissection.

Possible risks and complications

As with any operation, a neck dissection carries risks. Most people do well, but the following complications can occur:

• Shoulder weakness and stiffness. The spinal accessory nerve controls a major shoulder muscle. If this nerve is stretched, injured, or removed, it can cause shoulder drooping, weakness, difficulty raising the arm, and shoulder pain (accessory nerve weakness). This is one of the most common longer-term effects and is more likely with more extensive surgery.

• Numbness. Numbness of the neck, ear, and nearby skin is common because small sensory nerves are often affected (see great auricular nerve neuropathy).

• Lip or mouth weakness. A nerve near the jaw (the marginal mandibular branch of the facial nerve) can be affected, causing temporary or, less often, lasting weakness of the lower lip and an uneven smile (marginal mandibular nerve weakness).

• Chyle leak. Injury to a lymphatic channel (the thoracic duct), most often on the lower left neck, can allow milky lymph fluid to collect. This is uncommon but may require dietary changes, prolonged drainage, or occasionally further procedures (chyle leak).

• Seroma. A collection of clear fluid under the skin can form, which is one reason drains are used.

• Bleeding or hematoma. A collection of blood may develop and occasionally needs to be drained.

• Infection. Wound infections can occur and are treated with antibiotics and wound care.

• Thyroid and parathyroid issues (central neck surgery). When the central neck is dissected, the small parathyroid glands (which control calcium) and nearby nerves to the voice box can be affected, leading to low calcium levels (hypoparathyroidism) or voice changes (laryngeal nerve dysfunction). These are often temporary but can sometimes be lasting.

The specific risks depend on which levels and structures are involved, so the surgical team reviews the risks most relevant to each individual plan.

The role of physical therapy

Physical therapy is an important part of recovery, especially for protecting shoulder and neck function. Gentle range-of-motion and strengthening exercises are often started soon after surgery and continued as an outpatient. When the spinal accessory nerve has been stretched or affected, focused physical therapy can improve shoulder movement, reduce stiffness and pain, and help maintain quality of life. Sticking with a prescribed exercise program makes a meaningful difference in long-term shoulder and neck function.

How results are reviewed after surgery

After the operation, all removed tissue is examined under a microscope by a pathologist (see pathology). The pathology report describes how many lymph nodes were removed, how many contained cancer, the size of any cancer deposits, and whether cancer extended beyond the wall of a node (extranodal extension). These details help determine the stage of the cancer and guide any further treatment.

The care team reviews these results, often in a multidisciplinary meeting that includes surgeons, cancer specialists (medical and radiation oncologists), and others. Depending on the findings, additional treatment may be discussed, such as radiation therapy, radioactive iodine (for certain thyroid cancers), or systemic therapy. A follow-up visit is used to explain the pathology results, discuss next steps, and set up ongoing surveillance.