Neck surgery for the general surgeon

Initial assessment ( Box 8.1 )

A full clinical history is critical and should include not only features relating to the mass (site, duration, tenderness, growth, overlying skin changes) but also associated features which may point to the underlying diagnosis such as fevers, hoarseness, dysphagia, upper airway sounds and weight loss. Patient features including smoking, alcohol consumption and comorbidities may be critical in overall case management. On occasion, family history may be of interest, particularly in thyroid and parathyroid conditions which can be familial as in familial thyroid cancer and multiple endocrine neoplasia. Likewise, a brief occupational history may provide some clues such as a link between textiles industry workers and some head and neck malignancies. Establishing a previous medical history, specifically any previous malignancies or HPV and EBV exposure is useful.

The majority of neck masses requiring investigation arise within lymph nodes. However, salivary and thyroid masses are also common. Although vascular and neurogenic tumours are uncommon, an appreciation of such conditions is useful for forming a differential diagnosis ( Table 8.1 ).

In areas of the world where tuberculosis is endemic, tuberculous cervical lymphadenopathy is common. Patients present with cold collar and stud abscesses and may have systemic features of the infection. Such patients require an accurate diagnosis, and will often benefit from aspiration of pus in order to target antibiotic therapy. Open incision and drainage should be avoided as this often results in an unsightly chronic sinus.

Malignancy should always be considered when investigating a neck mass, and a full head and neck examination is indicated to screen for an upper aerodigestive tract primary lesion. When considering the high-risk sites for primary disease, an understanding of lymphatic drainage from the head and neck is critical. Malignancy from the oral cavity will tend to drain to the submental or submandibular (level I) nodal basin. Lesions more posterior in the throat (the oropharynx) will more commonly metastasize to the jugular nodal chain (level II/III/IV). Laryngeal and thyroid cancers spread first to nodes in the central (level VI) or low lateral (level III/IV) neck ( Fig. 8.1 ). When metastatic nodes are encountered in the posterior triangle (level V), primary disease may be present in the nasopharynx, scalp (skin cancer) or sites below the clavicle (lung, breast or gastrointestinal metastases to Virchow’s node). Lymphoma commonly presents with cervical nodal enlargement, and can affect any or all lymph node groups.

In order to assess all at-risk sites appropriately, visualisation of the mucosal surfaces of the upper aerodigestive tract is required. Although the oral cavity can be adequately assessed using a light, further examination requires mirror (indirect) or endoscopic (direct) assessment.

Having completed an examination, basic investigations including full blood count, erythrocyte sedimentation rate, glandular fever screen and chest X-ray will be considered on a case-by-case basis.

Following a full history and examination, some patients will require further investigation for an overt primary malignancy. However, a large percentage of patients will require further consideration of the neck mass without evidence of primary disease elsewhere.

Imaging

Ultrasound (US) has become widely accepted as routine in assessment of the neck mass. This non-invasive investigation provides an accurate assessment of the neck and allows targeted tissue sampling where appropriate. However, it has limitations. The accuracy of findings are operator dependent and the images produced are less useful for surgical planning than those from cross-sectional imaging. Certain areas of the neck including the parapharyngeal space and the central neck are poorly visualised on US. Despite this, the majority of neck masses which require further assessment should be considered for US.

Computed tomography (CT) scans have become increasingly available in modern clinical practice. When contrast enhanced, CT scans allow assessment of potential malignant features and accurately display the relationship of the mass to the great vessels of the neck. In addition, CT provides valuable information about the mucosal surfaces of the head and neck. When extended to the thorax, the mediastinal nodes and lungs can be assessed for metastatic disease and possible synchronous primary lesions. CT scans are performed rapidly, which limits movement artefact due to swallowing and breathing during the examination. However, dental amalgam produces significant artefact which may obscure the structures within the oral cavity and oropharynx.

Magnetic resonance imaging (MRI) has the advantage of not involving ionising radiation. In addition, dental amalgam is less of an issue than for CT. However, images take longer to capture which makes movement artefact more of an issue. Improved soft tissue definition and increasing availability has led some groups to adopt MRI routinely in preference to CT for assessment of the neck. For staging of certain mucosal head and neck malignancies in the nasopharynx, oropharynx and hypopharynx, it is now considered a gold standard approach to use MRI alongside CT.

Positron emission tomography (PET) scanning involves the use of a radiolabelled tracer (most commonly FDG-18F) to provide functional imaging. In head and neck surgery, it tends to be used for identification of unknown primary disease in the setting of squamous cell carcinoma within a neck node, and for detection of recurrent or residual disease following treatment.