October 28, 2004
Evaluation of the Neck Mass
A mass in the neck is a common clinical finding in patients who present to their Primary Care Physician. The differential diagnosis is broad, but in the adult patient malignancy must always be ruled out. Therefore, physicians must develop a systematic approach for developing a working diagnosis and management plan for the patient.
ANATOMYAccurate evaluation of a neck mass requires knowledge of the normal anatomy. The prominent landmarks of the neck are the hyoid bone, thyroid cartilage, cricoid cartilage, trachea, and sternocleidomastoid muscles (SCM). Prominence or asymmetry of any of these normal structures can often be mistaken for an abnormal mass. The SCM divides each side of the neck into two major triangles, anterior and posterior. The anterior triangle is delineated by the anterior border of the SCM laterally, the midline medially, and the lower border of the mandible superiorly. The borders of the posterior triangles are the posterior border of the SCM anteriorly, the clavicle inferiorly, and the anterior border of the trapezius muscle posteriorly.
It is convenient to use the level system to describe the location of lymph node disease in the neck. Level I contains the submental and submandibular nodes. Levels II through IV contain lymph nodes along the jugular vein (upper, middle and lower). Level V contains the lymph nodes located along the lower half of the spinal accessory nerve and the transverse cervical artery, posterior to the SCM. The supraclavicular nodes are included in the posterior triangle group. The pre- and paratracheal nodes, precricoid (Delphian) node, and perithyroidal nodes are found within level VI. Lymph nodes are located throughout the head and neck region and are the most common sites of neck masses. Fixed, firm, or matted lymph nodes and nodes larger than 1.5 cm require immediate investigation.
In general, neck masses in children are more commonly inflammatory than congenital or developmental and more commonly congenital than neoplastic. This distribution is similar in the young adult. However, the first consideration in the late adult should be neoplasia. The "rule of 80" is often applied, which states that 80% of non-thyroid neck masses in adults are neoplastic and that 80% of these masses are malignant.
The next consideration should be the location of the mass. The location of the mass is particularly important with respect to congenital and developmental masses, because such lesions are consistent in location. Branchial cleft cysts are almost always located anterior to the SCM, though first branchial anomalies are often found in the parotid or even postauricular areas. Thyroglossal duct cysts are often midline, and may be found at any location along the embryologic decent of the thyroid gland. Location of metastatic neck masses may be the key to identification of the primary tumor. It is important despite the general considerations of age and location to treat each case individually.
The lymphatic flow in the neck follows a predictable pattern and the presence of a mass in a particular location may offer clues to identifying a primary tumor or site of infection. Level I nodes often indicate disease in the anterior oral cavity. Level II, III, and IV nodes often indicate disease in the oropharynx/hypopharynx/ endolarynx. Midline tumors may metastasize to contralateral nodes. Level V nodes often indicate disease in the nasopharynx. Supraclavicular nodes usually indicate dis ease below the level of the clavicles.
Evaluation of the patient with a neck mass must begin with a careful and complete history and a thorough head and neck examination. The patients age and die size and duration of the mass are the most significant predictors of neoplasia, with the risk of malignancy being greater in older individuals. A thorough review of the developmental time course of the mass, associated symptoms, personal habits, and prior trauma, irradiation or surgery is important. Inquiries about smoking and alcohol use, fever, pain, weight loss, night sweats, exposure to tuberculosis, foreign travel and occupational/sexual history should be made. Symptoms of dysphagia, unilateral otalgia, trismus and/or hoarseness most likely represent a malignant process.
A full physical examination should be carried out in all patients. All mucosal surfaces of the nasal cavity, nasophaiynx, oropharynx, larynx should be visualized by direct examination or by indirect mirror or fiberoptic visualization. The Primary Care Physician should be able to visualize all areas except for the nasopharynx, larynx, and hypopharynx which would require special equipment for direct visualization. The oral and oropharyngeal surfaces, including the base of tongue, should be digitally palpated in addition to the neck mass. Emphasis on location, mobility and consistency of the neck mass can often place the mass within a general etiologic grouping, such as vascular, salivary, nodal/ inflammatory, congenital or neoplastic. Unilateral otalgia with normal otoscopy should direct the examination to the tonsil, tongue base, supraglottis, and hypopharynx. A unilateral serous effusion in the adult patient may represent a primary tumor within the nasopharynx or mass within the parapharyngeal space. Evaluation of these areas is mandatory in any patient who presents with unilateral effusion.
After a complete head and neck examination and history, additional diagnostic studies may be warranted. The following studies may be useful in select patients.
FINE NEEDLE ASPIRATION BIOPSY (FNAB)
Currently, FNAB is the standard of diagnosis for neck masses. I perform FNAB in all patients, usually following an initial CT scan with contrast. FNAB separates inflammatory and reactive processes from neoplastic lesions, either benign or malignant. FNAB is extremely accurate, especially in the hands of a skilled Cytopathologist. The sensitivity and specificity of fine-needle aspiration and biopsy exceed 90%. There are no contraindications to FNAB. Patients who likely have a vascular tumor or paraganglioma don't require FNAB; however, because of the small needle used, signigicant morbidity following FNAB of a highly vascular tumor would be extremely unlikely. Needle-track seeding of tumor is not a concern with the fine needles used today, though has been reported with use of larger bore needles and core biopsy. A 25G needle is usually recommended. A skilled Cytopathologist is critical to the efficacy of FNAB. On-site evaluation carries the advantage of assessing specimen adequacy, which reduces the number of unsatisfactory specimens.
Ultrasonography has limited utility in the evaluation of the adult neck mass. However, it can be useful in differentiating solid from cystic masses and congenital cysts from solid lymph nodes and glandular tumors. It is also useful in evaluation of thyroid nodules/ masses. Ultrasound is often helpful in localizing a neck mass for guided FNAB.
COMPUTED TOMOGRAPHY (CT)
CT scanning of the neck with contrast is considered the most useful initial imaging study in the evaluation of the neck mass. It can define the origin and full extent of deep, ill-defined masses, and when used with contrast can delineate vascularity or blood flow. It can be helpful in delineating the site of a primary tumor. Metastatic nodes will commonly show central lucency, size greater than 1.5 cm, and an ill-defined border.
MAGNETIC RESONANCE IMAGING
MRI provides much of the same information as CT, and is generally not necessary as part of an initial evaluation. It is currently better for upper neck and skull base masses due to possible dental artifact on CT It is better than CT in evaluation of the pulsatile mass or mass with a bruit or thrill. I reserve MRI/MRA for work-up of the vascular mass, a suspected paraganglioma, or selected parotid masses.
Routine use of PET scanning is likely not necessaiy in evaluation of the patient with a neck mass. It may be helpful to localize a primary tumor in a patient with a metastatic node, to detect distant metastasis, or to rule-out recurrence in a patient with a previously treated malignancy. PET scanning may also be helpful in localizing the primary tumor in a patient with known metastatic carcinoma with a primary tumor which has not been localized by endoscopy or other diagnostic tests.
NODAL MASS WORKUP IN THE ADULT
An asymptomatic cervical mass is the presenting symptom in about 12% of head and neck cancer cases. Of these cancers, approximately 80% are squamous cell carcinoma (SCCa). A history of alcohol and/or tobacco use increases the chance of malignancy, though SCCa is being seen increasingly in non-smokers/non-drinkers. A tender, mobile mass or a high suspicion of inflammatory adenopathy with an otherwise negative examination may warrant a clinical trial of antibiotics and observation not to exceed two weeks with close follow-up. A mass which persists after broad spectrum antibiotic therapy must be considered malignant until proven otherwise. In a patient with a persistent neck mass, I obtain a CT scan of the neck with contrast, a CXR (or CT if I am convinced of a malignancy or if the inferior border of the mass extends into the chest/mediastinum), and perform FNAB in all cases.
If FNAB confirms malignancy and careful examination in the office does not identify a primary site, the entire aerodigestive tract mustbe examined endoscopically under anesthesia. Biopsies should be performed on any suspicious mucosal lesions. Suspicious lesions noted on preoperative scanning should also be biopsied. If no lesions or imaging abnormalities are noted, biopsies of the nasopharynx, tonsils (bilateral tonsillectomy), base of tongue, and pyriform sinuses should be obtained. It is important at this time to examine thoroughly all areas of the aerodigestive mucosa, including the esophagus, to identify the primary or any synchronous lesions, which occur in between 10% and 20% of patients with head and neck malignancies.
In a recent study of SCCa of the neck from an unknown primary at the University of Florida, the primary tumor was able to be detected about 40% of the time. In approximately 80% of these cancers, the base of tongue or tonsil was the culprit. The ability to find the primary lesion greatly depended on suspicious findings during physical examination and on radiographie studies. If no suggestive findings on exam or CT were obtained the yield dropped to below 20%.
If a negative/equivocal FNAB is obtained yet suspicion for malignancy persists, an open excisional biopsy of the cervical lymph node may be performed. Open biopsy is performed as a last resort if all other studies are non-diagnostic. The patient and surgeon should be prepared to proceed with a complete neck dissection depending on results of frozen sections. If the biopsy shows only inflammatory or granulomatous changes, culture of the tissue is warranted. A result of adenocarcinoma or lymphoma dictates closure of the wound and further workup and staging procedures prior to further treatment decisions.
It is reasonable for the Primaty Care Physician to perform the initial work-up and establish a treatment plan for the patient. A complete physical exam is always warranted, searching for evidence of lymphadenopathy or systemic disease outside of the head and neck. Careful head and neck examination can often isolate the primary pathology and help guide the physician toward specific diagnostic tests. A trial of antibiotics can be initiated if infection is suspected. More than one course of antibiotic is likely not warranted before additional testing is recommended. If the history suggests an infectious process, additional testing can be ordered such as CBC with differential, HIV testing, PPD, EBV testing, etc... If the neck mass persists, imaging studies and additional bloodwork (i.e., TFTs) can be ordered based on the location of the mass, and arrangements made for Otolaryngology evaluation.
Thyroid neoplasms, either benign or malignant, are a leading cause of anterior compartment neck masses in all age groups. Lymph node metastasis may be the initial symptom in 15% of papillary carcinomas and micrometastasis may be present in over 90% of cases. Fine-needle aspiration of thyroid masses has become the standard of care, replacing ultrasonography and radionuclide scanning in the assessment of thyroid nodules, although ultrasound may be performed to determine if the mass is cystic or to guide FNAB for small nodules. It has been shown that FNAB has decreased the number of patients being treated with surgery, increased die number of malignant tumors found at surgery, and doubled the number of cases being followed up. Unsatisfactory aspirates should be repeated, and negative aspirates should be followed up with a repeat examination and FNAB a month later.
Lymphoma can occur in all age groups, but is a more common neoplastic process in pediatric and young adult groups. As many as 80% of children with Hodgkins disease have a neck mass. Progressive enlargement of a lateral neck mass is often the only sign of disease in the head and neck. Systemic signs of fever, hepatosplenomegaly and diffuse adenopathy should be sought. The mass often appears discrete, rubbery and nontender. FNAB is the first line diagnostic test, and when it suggests lymphoma, an open biopsy with histologic examination is appropriate. Flow cytometry can often be performed on cellular specimen from a simple FNA. Work-up of head and neck lymphoma includes CT scans of the chest, abdomen, head and neck and bone marrow biopsy.
An enlarging mass anterior or inferior to the ear or at the angle of the mandible or submandibular triangle should raise suspicion for a primary salivary gland tumor. Benign tumors are usually asymptomatic, however rapid growth, skin fixation or cranial nerve palsies (VII, XII and lingual) suggest malignant disease. I perform FNAB and CT scan with contrast in all patients with suspected salivary neoplasms. FNAB has been shown to reduce the number of patients being treated with surgery by 33%. Some apparent neoplastic lesions on exam, may be intraparotid lymph nodes, localized sialadenitis, benign lymphoepithelial lesions or cysts. These lesions can often be followed closely, and may not require excision. The accuracy of FNAB in salivary glands is greater then 90% and more exact in benign than malignant tumors. If signs of malignancy are noted, FNAB may facilitate surgical planning and patient counseling.
CAROTID BODY AND GLOMUS TUMORS
These tumors are rare in the pediatric patient. In adults, they classically appear in the upper anterior triangle at the carotid bifurcation as a pulsatile, compressible mass, which is mobile from side to side. A bruit or thrill is present and in glomus vagale tumors, the ipsilateral tonsil may pulsate and/or deviate to the midline. The diagnosis is confirmed by angiography or CT scan. In the elderly patient, close observation or treatment with irradiation to arrest growth is adequate. In young patients, a small tumor should be resected under hypotensive anesthesia. Preoperative embolization is used routinely. Preoperative measurement of catecholamine release should precede removal.
Lipomas are ill-defined, soft masses usually appearing in patients over the age of 35 years. They are usually asymptomatic and diagnosed by clinical findings. Diagnosis is confirmed by excisional biopsy.
Neurogenic tumors or peripheral nervous system tumors arise from neural crest derivatives including Schwarm cells, perineurial cells, and fibroblasts. They include schwannomas (neurilemmoma and neurinoma), neurofibromas and malignant peripheral nerve sheath tumors (MPNST). An increased incidence is associated with heritable neurofibromatosis (NF) syndromes. Of the neurogenic tumors, schwannomas occur most commonly in the head and neck region. Most are sporadic cases, and when extracranial, 25 to 45% will occur in the head and neck. MPNST is uncommon in the head and neck region.
Schwannomas are benign, solid neurogenic tumors that can occur at any age, but are most common between the ages of 20 and 50 years. Those arising in the neck commonly occur in the parapharyngeal space. They usually present as a solitary, slowly enlarging and painless mass. On physical examination, they usually cause medial tonsillar displacement. Those originating in the vagus nerve may present with hoarseness and/or vocal cord paralysis, and when originating in the sympathetic chain may be associated with Homer's syndrome. MRI is helpful in diagnosis and shows displacement of the internal carotid artery anteriorly and laterally. For benign lesions, conservative surgical excision is the treatment of choice.
CONGENITAL AND DEVELOPMENTAL MASSES
BRANCHIAL CLEFT CYSTS
A branchial cyst usually presents as a smooth, fluctuant mass underlying the SCM (second arch - most common) and often seems to appear rapidly after an upper respiratory tract infection. These masses most commonly occur in late childhood or early adulthood, but may occur later in life also. These masses are commonly located along the anterior border of the SCM. The less common 1st branchial cyst occurs along the angle of the mandible or below the ear lobe. CT scan will typically show a cystic mass along the border of the SCM, but is not diagnostic because cystic masses are not always benign. Papillary carcinoma of the thyroid and SCCA of the nasophaiynx, tonsil, and base of tongue (i.e., Waldeyer's ring), often will produce cystic metastases. Therefore, when faced with a cystic mass in the neck, FNAB may help the surgeon avoid the pitfall of excisional biopsy, which would be particularly detrimental in the patient with a SCCA. In general, treatment of branchial cleft anomalies is with initial control of infection, followed by surgical excision.
THYROGLOSSAL DUCT CYSTS
This is the most common congenital neck mass, which presents as a midline or near-midline mass that usually elevates on swallowing or protrusion of the tongue. This clinical finding distinguishes the TDC from other midline masses, such as lymph nodes, dermoids or ectopic thyroid tissue, which are included in the differential. Treatment is surgical removal including the midportion of the hyoid bone (Sistrunk procedure) after resolution of infection.
Lymphangiomas and hemangiomas are considered congenital lesions almost always present within the first year of life. While lymphangiomas usually remain unchanged into adulthood, hemangiomas most often resolve spontaneously. The lymphangioma mass is soft, doughy, and ill-defined. CT or MRI may help define the extent of the neoplasm, and treatment includes excision for easily accessible lesions or those affecting vital functions. Often surgical treatment precipitates further disease and recurrence is common. Hemangiomas, on the other hand, often appear bluish and are compressible. CT or MRI again help the diagnosis and define the extent of disease. Surgical treatment is reserved for lesions with rapid growth, associated thrombocytopenia or involvement of vital structures that fail medical therapy (steroids, Interferon).
Acute lymphadenitis is very common at some point inalmost everyone's life. The presentation with marked tenderness, torticollis, trismus and dysphagia with systemic signs ofinfection is seldom a diagnostic challenge to the clinician and the source of the reactive lymphadenopathy is usually easily identified. Initial treatment with directed antibiotic therapy and follow up is the rule.
Inflammatory nodes generally regress in size. If the lesion does not respond to conventional antibiotics a biopsy is indicated after complete head and neck work-up. Other indications for FNAB of lymphadenopathy include progressively enlarging nodes, a solitary and asymmetric nodal mass, supraclavicular mass or persistent nodal masses without active infectious signs.
These infections usually develop over weeks and months, often with minimal systemic complaints of findings. They may be the result of typical or atypical mycobacteria, actinomycosis, sarcoidosis, or cat-scratch fever (Bartonella). The glands tend to be firm, with some degree of fixation and injection of the overlying skin. Tuberculosis is now rarely seen in our population, though is becoming more common now with HIV. Atypical mycobacteria and cat- scratch fever are more common and more prevalent in the pediatric age group. Atypical mycobacterial infection usually involves anterior triangle lymph nodes often with brawny skin, induration and pain, while cat-scratch commonly involves the preauricular or submandibular nodes. Typical TB lymphadenitis often responds to anti- tuberculosis medications. Cat-scratch often undergoes spontaneous resolution with or without antibiotic treatment. Atypical mycobacterial infection usually responds to complete surgical excision.
The differential diagnosis of a neck mass is extensive and varies with the age of the patient at presentation. A thorough work-up including an accurate history and complete head and neck examination often narrows the diagnostic possibilities. The fine needle aspiration biopsy has become an invaluable tool to aid clinicians in the evaluation of the neck mass and is safe, accurate, and cost- effective with minimal complications. The possibility of malignancy in any age group, especially in the late adult group, should never be overlooked. Close follow-up and aggressive pursuit of a diagnosis with appropriate work-up facilitates a timely and accurate treatment plan, which is essential to a favorable outcome.
SYMPTOMS OF DYSPHAGIA, UNILATERAL OTALGIA, TRISMUS AND/OR HOARSENESS MOST LIKELY REPRESENT A MALIGNANT PROCESS.
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CHARLES RUHL, MD
Charles Ruhl, MD, is Assistant Clinical Professor, Department of Surgery Brown Medical School, and Assistant Clinical Professor, Department of Otolaryngology-Head & Neck Surgery, Tufts University School of Medicine.
Charles Ruhl, MD
130 Waterman Street
Providence, RI 02906
Fax: (401) 274-0672
Email: [email protected]
Copyright Rhode Island Medical Society Oct 2004