Understanding the basic evaluation of the neck mass is essential in determining when a mass is insignificant or significant, and potentially malignant. Beginning with an understanding of neck anatomy, a thorough history and physical exam, this basic evaluation can become straightforward and well directed.
Etiology
Most neck masses are secondary to enlargement of lymph nodes. Palpable masses of the thyroid are also relatively common. Less common masses arise from the major salivary glands or have congenital origins. It is uncommon to see neck masses arising from bone, cartilage, muscle, vasculature, or nerves of the head and neck.
Anatomy
The Sternocleidomastoid muscle defines the anterior and posterior triangle of the neck. The laryngo-tracheal complex defines the central neck. The majority of the parotid gland is located within the neck rather than in the lateral face and the submandibular gland is located below and just anterior to the angle of the mandible. The lymph nodes of the neck are described in six basic levels: level 1 (submandibular and submental), levels 2, 3, and 4 (high, mid, and low jugular chain), level 5 (posterior triangle) and level 6 (central neck).
History
A patient’s age, duration and progression of the neck mass, and associated symptoms if any, often can significantly narrow the possible diagnosis. In general, the potential for neoplasm increases with increasing patient age. In all age groups, a prior upper respiratory infection or other inflammatory event increases the likelihood of simple lymphadenitis, especially when the neck mass is tender.
Non-tender neck masses present for more than two weeks are more likely to be neoplastic. Young adults with chronic non-tender nodal enlargements in the anterior or posterior triangle of the neck may have Hodgkin’s lymphoma. Seventy percent of Hodgkin’s disease is first diagnosed in the neck and only 25% of these will have B symptoms (fever, chills, night sweats or weight loss). Less commonly metastatic papillary carcinoma of the thyroid is present.
Patients over the age of 40 with a history of heavy tobacco use and/or alcohol use are at greatest risk of having a mucosal based squamous cell cancer metastatic to the cervical lymph nodes. These patients will often have chronic symptoms of discomfort within the oral cavity or pharynx, referred otalgia, or hoarseness.
Although tobacco and alcohol are the primary risk factors for this disease, high-risk HPV is a causative agent for carcinomas of the tonsils and tongue base. These are seen most in middle-aged persons. These patients often have relatively large lymph node metastasis and usually have an asymptomatic primary tumor in the pharynx.
Exam
Definition of the size, location, and physical qualities of the neck mass provide insight into its origin.
Masses within the parotid gland are generally neoplastic and 85% are benign. Facial weakness or pain with a parotid mass suggests malignancy. Fifty percent of masses within the submandibular gland are malignant. Although primary malignancy of the parotid or submandibular glands can occur in all age groups, skin malignancies of the face and scalp can produce nodal metastasis in these areas. This is seen most frequently in elderly persons with squamous cell carcinoma of the skin but can also be seen in younger persons with metastatic melanoma. All patients with a neck mass deserve a thorough exam of the skin.
A round and cystic mass within the anterior triangle of the neck is most likely a branchial cleft cyst in a person age 30 or younger. In a person over age 30, the mass should be considered malignant even if it looks to be a brachial cleft cyst on exam and imaging. A cystic mass in the midline above the hyoid is often a thyroglossal duct cyst. This is the most common congenital neck cyst, these can be found at all ages but as with branchial cleft cysts, usually present in younger patients.
A firm non-tender neck mass in the anterior or posterior triangles of the neck should be considered malignant and a complete exam of the mucosal surfaces of the oral cavity, pharynx and larynx are performed to seek a primary tumor site.
Evaluation and Management
For tender neck masses present for two weeks or less, a trial of observation with or without antibiotic therapy, with planned clinic follow-up is appropriate. The exception would include those patients who have features suggesting abscess where aspiration or surgical drainage may be required.
For almost all patients with a non-tender neck mass, except suspected vascular tumors, fine needle aspiration is a good next step. However, false results do occur and the technique is poor for ruling out lymphoma.
Imaging for patients suspected to have a thyroid malignancy should consist of ultrasound of the neck. Use of iodine contrast in these patients can delay I-131 therapy. For all others, iodine contrast enhanced CT of the neck is the best initial study. CT of the neck is often helpful in defining previously unrecognized abnormalities such as additional nodal enlargement and lesions suspicious for primary tumor sites.
Referral to head and neck surgical oncologist is reasonable for patients with clear cut or less well defined causes for their neck mass. Patients with malignancies of the head and neck are offered the services of the multi-disciplinary head and neck oncology team at the UW Carbone Cancer Center.
For more information on the treatment of head and neck masses, please visit our head and neck cancer webpage.