NECK AND LYMPH NODES

Examination of the neck is a natural extension of a routine dental examination and includes examination of the submandibular and cervical lymph nodes (draining the oropharynx and other tissues of the head and neck and anastomosing with lymphatics from the abdomen, thorax, breast, and arm), the midline structures (hyoid bone, cricoid and thyroid cartilages, trachea, and thyroid gland), and carotid arteries and neck veins.
46
(Examination of the submandibular and sublingual salivary glands was described in the preceding section.) With the patient’s neck extended, note the clavicle and the sternomastoid and trapezius muscles, which define the anterior and posterior triangles of the neck. Palpate the hyoid bone, the thyroid and cricoid cartilages, and the trachea, noting any displacement or tenderness. Palpate around the lower half of the sternomastoid muscle, and identify and palpate the isthmus and wings of the thyroid gland below and lateral to the thyroid cartilage, checking for any nodularity, masses, or tenderness. If local or generalized thyroid enlargement is suspected, check to ascertain whether the mass moves up and down with the trachea when the patient swallows. Observe the external jugular vein as it crosses the sternomastoid muscle, and with the patient at an angle of approximately 45˚ to the horizontal, note any distension and or pulsation in the vein. Distension of >2 cm above the sternal notch is abnormal; in severe right-sided heart failure, distension as far as the angle of the mandible may be seen. Place the diaphragm of the stethoscope over the point of the carotid pulse, and listen for bruits or other disturbances of rhythm that may indicate partial occlusion of the carotid artery.
Palpate for lymph nodes in the neck (Figure 2-2), commencing with the most superior nodes and working down to the clavicle. Palpate anterior to the tragus of the ear for preauricular nodes; at the mastoid and base of the skull for

posterior auricular and occipital nodes; under the chin for the submental nodes; and further posterior for submandibular and lingual-notch nodes (usually palpated when the submandibular salivary gland is examined). The superficial cervical nodes lie above the sternomastoid muscle; the deep cervical nodes lie between the sternomastoid muscle and cervical fascia. To examine the latter, ask the patient to sit erect and to turn his or her head to one side to relax the sternomastoid; use thumb and fingers to palpate under the anterior and posterior borders of the relaxed muscle, and repeat the procedure on the opposite side. Next, palpate the posterior cervical nodes in the posterior triangle close to the anterior border of the trapezius muscle. Finally, check for supraclavicular nodes just above the clavicle, lateral to the attachment of the sternomastoid muscle.
Normal lymph nodes may be difficult to palpate; enlarged lymph nodes (whether due to current infection, scarring from past inflammatory processes, or neoplastic involvement) are usually readily located. Many patients have isolated enlarged and freely movable submandibular and cervical nodes from past oral or pharyngeal infection. Nodes draining areas of active infection are usually tender; the overlying skin may be warm and red, and there may be a history of recent enlargement. Nodes enlarged as the result of metastatic spread of a malignant tumor have no characteristic clinical appearance and may be small and asymptomatic or grossly enlarged. Classically, nodes enlarged due to cancer are described as “fixed to underlying tissue” (implying that the tumor cells have broken through the capsule of the lymph node or that necrosis and inflammation have produced perinodular scarring and adhesions), but this feature will usually be absent except with the most aggressive or advanced tumors. Gradually enlarging groups of nodes in the absence of local infection and inflammation are a significant finding that suggests either systemic disease (eg, infectious mononucleosis or generalized lymphadenopathy associated with human immunodeficiency virus [HIV] infection) or a lymphoid neoplasm (lymphoma or Hodgkin’s disease); such a finding justifies examination for (or inquiry about) lymphoid enlargement at distant sites, such as the axilla, inguinal region, and spleen, to confirm the generalized nature of the process. A successful outcome to cancer treatment is dependent on early detection and treatment, and hence the need for rapid followup investigation whenever unexplained lymph node enlargement is detected during examination of the neck. Enlargement of supraclavicular and cervical nodes may occur from lymphatic spread of tumor from the thorax, breast, and arm as well as from tumors of the oral cavity and nasopharynx. Conditions to be considered in a patient with cervical lymph node enlargement include acute bacterial, viral, and rickettsial infections of the head and neck (eg, acute abscesses, infectious mononucleosis, cat-scratch disease, and mucocutaneous lymph node syndrome); chronic bacterial infections, such as syphilis and tuberculosis; leukemia, lymphoma, metastatic carcinoma, collagen disease, and allergic reactions (especially serum sickness); and sarcoidosis.