Management of lateral neck masses in adults

One of the most important considerations in an adult presenting with a lump in the neck is that the mass may represent a metastatic deposit from a primary cancer, often but not always in the upper respiratory or alimentary tract (fig 1). This is particularly so for middle aged or elderly patients, especially those who have smoked. In these groups of patients it is important that the primary tumour is found quickly—preferably without open biopsy—so that correct management of the disease can be instituted.¹ Often, however, there are avoidable delays in making the diagnosis and obtaining the complete clinical picture. Therefore, an appropriate initial referral must be made for examination of the upper aerodigestive tract, and all those who play a part in the management of neck masses should be aware of the role of fine needle aspiration cytology.

Summary points

• 75% of lateral neck masses in patients over 40 years are caused by malignant tumours

• In the absence of overt signs of infection, a lateral neck mass is metastatic squamous cell carcinoma or lymphoma until proved otherwise

• The primary tumour can be detected in 50% of patients by clinical examination alone and in a further 10-15% by panendoscopy of the upper aerodigestive tract

• Fine needle aspiration biopsy is an accurate, sensitive, inexpensive, and rapid technique that can be performed in the clinic

• Excisional and incisional biopsy of cervical metastases results in a 2-3 times increased incidence of local treatment failure when compared with fine needle aspiration cytology

• Excisional biopsy of parotid tumours risks damage to the facial nerve and seeding of the wound, and recurrence may develop up to 20 years after the first attempt at resection

Figure 1.

Location of cervical lymph nodes most frequently affected by metastasis from named primary sites in head and neck

Methods

This review is based on our experience in clinical practice. The data were obtained by electronically searching Medline (1966-99) with the key words neck mass, head and neck neoplasms, and needle biopsy, and focuses on diagnosis, surgery, and management.

The clinical issue

More than 75% of lateral neck masses in patients older than 40 years are caused by malignant tumours, and the incidence of neoplastic cervical adenopathy continues to increase with age. It is difficult to make accurate statements about the percentage of masses that fall into one or other disease grouping as there are too many variables in published data. Nevertheless, in one large series of 8500 patients with head and neck neoplasms diagnosed over a 10 year period, 475 had presented with isolated lateral neck masses.² Overall, 190 patients (40%) in this subset had metastatic squamous cell carcinoma from unknown primary sites, 188 (39.5%) had lymphoma, and the remainder had either benign disease (78 patients, 16.5%), sarcoma (10, 2%), or chemodectomas (9, 2%). Several authors have investigated the origin of metastatic squamous cell carcinoma in patients with enlarged cervical lymph nodes.^3–5 In one of the largest series (267 patients), 74% of enlarged cervical nodes had developed from head and neck primaries and only 11% had come from primaries outside that region.¹ In the absence of any overt signs of infection, therefore, a lateral neck mass in an adult is either a metastatic squamous cell carcinoma or a lymphoma until proved otherwise.

Controversy over open biopsy

The possible adverse effects of excisional or incisional biopsy as a primary diagnostic tool in lateral neck masses is, and has been, strongly debated. In the event that the mass is a lymphoma, adenocarcinoma, sarcoma, metastasis from a primary outside the head and neck, or inflammatory node, few would argue that anything other than accelerating the diagnostic process had been achieved, even though fine needle aspiration cytology might have avoided the need for urgent open biopsy. Metastatic squamous cell carcinoma is possibly different, and the long term influence of open biopsy should be considered carefully. Several series of patients with metastatic squamous cell carcinoma in cervical lymph nodes have been analysed in the search for prognostic indicators. Most series suggest that open biopsy of the metastatic node, advanced age, and nodal stage have an adverse effect on survival.¹,⁶ Others have found that open biopsy is detrimental to clinical management as it makes subsequent examination of the neck more difficult, encourages fungation, increases the risk of subsequent recurrence in the neck, and entails an unnecessary hospital admission and general anaesthetic for the patient.^7–9 For example, in a series of 190 patients with cervical metastases from unknown primaries, excisional and incisional biopsy of the cervical nodes increased the incidence of local failure 2-3 times when compared with fine needle aspiration biopsy.² The evidence for this increased morbidity may not be particularly robust, perhaps even contentious, but while doubt exists most clinicians err on the side of caution.

Some series suggest that radiotherapy can eliminate recurrence in the neck, the most serious complication. Prognostic factors were investigated in 508 patients with head and neck squamous cell carcinoma and positive neck nodes who were treated by radiotherapy to the primary lesion with or without dissection of the neck. No detrimental effect on neck control, distant metastases, or cause specific survival could be found in the 66 patients who had had preliminary open biopsy.¹⁰ Evidence to support this contention from smaller series has been published.¹¹ It is doubtful whether the case for or against open biopsy of cervical nodes containing squamous cell carcinoma will ever be proved. In reality, however, this need not be the case. A body of opinion recommends that patients who have had preliminary open biopsy should receive radiotherapy either as the only form of treatment or in addition to surgery.¹⁰,¹¹

The problem

The primary site for squamous cell carcinoma can be detected in only about 50% of patients by a thorough clinical examination alone, and in a further 10-15% by panendoscopy of the upper aerodigestive tract. For those in whom surgery was necessary and could in itself have been curative, radiotherapy would have been avoided. The short and long term discomfort of mucositis and oropharyngeal dryness might have been completely unnecessary. A large number of patients with primary squamous cell carcinomas of the head and neck develop second primary tumours in the same region within five years.¹² Percentage estimates of this subgroup of patients vary between centres, but values of 15-25% are quoted. To make matters worse, 10-30% of these patients develop third and fourth primaries in the head and neck. Such are the problems of tobacco related diseases. Future treatment options may have been compromised by primary radiotherapy, and the chance of long term survival with organ preservation might have been removed.

Benign tumours

In the category of benign tumours, it is difficult to consider any group of diseases more important than salivary gland tumours and pleomorphic adenoma in particular. Pleomorphic adenomas of the parotid gland are sometimes misdiagnosed and subjected to excisional biopsy. Regardless of risks to the facial nerve, complete excision by enucleation is virtually impossible, some of these tumours have a significant myxoid component and rupture, several have pseudopodial outgrowths, and others are poorly encapsulated. In these circumstances the wound is inevitably seeded, and recurrence is likely.¹³,¹⁴ Management of recurrent disease is exceptionally difficult and demands special surgical skills and postoperative radiotherapy if the patient is to have any chance of cure and reasonable facial nerve function.¹⁵,¹⁶ Recurrences are usually multiple, are sometimes widespread, develop up to 20 years or more after the first attempt at resection, and have the potential for malignant change.

Most surgeons advise patients who have had open biopsy of a pleomorphic adenoma to undergo a superficial parotidectomy and excision of the biopsy scar. Some offer radiotherapy after surgery to reduce the chance of recurrence still further.¹⁷ These patients need to be kept under review for decades because the risk of developing a recurrence does not diminish over time and the consequences to the facial nerve can be devastating. Much of this could be avoided. The diagnosis of pleomorphic adenoma is relatively straightforward with fine needle aspiration cytology, and seeding of salivary gland tumours with this technique has not been reported. One further advantage is that the surgeon can be forewarned about the presence of a potentially curable malignant salivary tumour—one that may need to be resected by someone with special surgical expertise.

Deriving a diagnosis

Symptoms of sore throat, unilateral hearing loss, earache, and hoarseness should be sought. However, no symptom or complex of symptoms is strongly correlated with early head and neck cancer for any subsite except the glottis,¹⁸ for which voice change or hoarseness is highly significant. The patient should be referred promptly to a clinician who can examine the neck and upper aerodigestive tract.

Conventionally, the neck can be divided into anatomical triangles. The lymph nodes in each triangle have defined drainage areas (fig 1). Careful palpation of these triangles restricts the differential diagnosis to the structures at that site and suggests the drainage areas that must be scrutinised. Examination of the oral cavity, pharynx, larynx, post nasal space, and thyroid gland is mandatory.

Fine needle aspiration cytology offers an accurate, sensitive, inexpensive, and rapid method for evaluation of a cervical adenopathy or mass. In a study of the diagnostic reliability of 350 aspiration biopsies of lymph nodes, a sensitivity of 85% and a specificity of 99% were achieved.¹⁹ The only aspirate giving a false positive result was from a reactive node mistaken for a lymphoma, and of the nine aspirates that gave false negative results only one was a carcinoma. A case can be made for performing fine needle aspiration cytology regardless of the clinical findings. Better results are always obtained if an experienced person aspirates the mass. Slide preparation is critical for accurate diagnosis, and immediate inspection in a specialised cytopathology clinic allows additional material to be acquired if the aspirate is acellular or if further material is required for immunocytochemistry or culture (fig 2).²⁰ For patients with poorly defined or deep seated lesions, image or ultrasound guidance can be used.²¹,²² Inevitably, there will be cases in which the validity of fine needle biopsy is called into question. In these circumstances an open biopsy may be the only way to determine the diagnosis.

Differential diagnoses of lateral neck masses

• Developmental: branchial cyst, haemangioma, laryngocoele

• Skin and subcutaneous tissues: sebaceous cyst, lipoma

• Lymph nodes: Infective:Viral: Epstein-Barr virus, HIVBacterial: staphylococcus, tuberculosis, cat scratch,  brucellaProtozoa: toxoplasma, leishmaniasisFungal: histoplasmosis, blastomycosis,  coccidiomycosisGranulomatous: sarcoid, foreign body reactionNeoplastic: lymphoma, metastasis

• Carotid sheath: aneurysm, carotid body tumour, vagal or sympathetic neuroma

• Salivary gland (parotid or submandibular)Infective: sialadenitis, sialolithiasisAutoimmune: Sjögren's syndromeNeoplasticMiscellaneous: AIDS related disease

Figure 2.

Fine needle aspiration biopsy of a parotid mass. The patient had a recurrence of pleomorphic adenoma, which had been enucleated 10 years earlier. (Reproduced with patient's permission)

Patients should undergo computed tomography of the head, neck, and chest. This should be followed by endoscopic examination of the upper aerodigestive tract under general anaesthetic if no cause for the mass is found on clinical examination and fine needle biopsy diagnoses or if metastatic squamous cell carcinoma is suggested.²³ At endoscopy, biopsies should be taken of any suspicious area detected by computed tomography and also samples taken from the base of tongue and nasopharynx, as neoplasms from both these sites often present with an isolated neck metastasis. Tonsillectomy on the side of the lesion is prudent. The role of positron emission tomography has yet to be determined, but on occasion it can prove helpful in finding either the primary tumour or unsuspected secondaries.²⁴

Not every lateral neck mass in an adult should be considered a squamous cell carcinoma; the differential diagnoses of lateral neck masses are extensive (see box). Fine needle aspiration cytology continues to have a role in the diagnosis of infective and granulomatous conditions. When these are suspected, additional samples must be taken for culture and blood taken for serological tests. Cytological diagnosis of non-specific reactive lymphadenopathy should be confirmed by a period of careful observation and either repeat fine needle aspiration cytology or excisional biopsy if the swelling does not resolve completely. Tuberculosis, goitre, HIV related disease, sarcoid, chemodectomas, branchial cysts, laryngocoeles, lymphoma, and adenocarcinoma can and often do present as solitary neck masses. The commonest disease should be excluded first and expert advice promptly sought.