CC
A 63-year-old male is referred for evaluation of a mass in his neck.
HPI
The patient reports a several-month history of a midline submandibular neck swelling that he associated with an abscessed tooth. A mandibular tooth was subsequently removed by his dentist, but the patient indicates no improvement with his submandibular swelling.
The patient reports that the area is slightly tender. Of note, swellings of neoplastic origin are unlikely to be painful or tender. He further indicates the swelling under his jaw had been present for many months, suggesting a chronic process, but had become especially bothersome over the past several weeks. There are no associated symptoms of hoarseness or dysphagia as would be seen with impingement of a mass on the vocal cords or posterior oropharynx. There is no history of recent weight loss, a nonspecific constitutional symptom suggestive of a malignant process. He does not have any complaints of airway obstruction or difficulty breathing. Airway compromise, either caused by an expanding mass or infectious processes (e.g., cellulitis), requires acute intervention.
PMH/PDH/medications/allergies/SH/FH
The patient has an unremarkable past medical and surgical history. There is no family history of similar presentations. He does not have any social risk factors for neoplastic causes of his neck mass such as smoking or alcohol abuse. His abscessed tooth could cause submandibular swelling, but this would be unlikely because of the persistence of symptoms after removal of the infectious source. Patients should be questioned regarding a history of malignancies that may present with a metastatic lesion in the neck.
Examination
General. The patient is a well-developed and well-nourished male in no apparent distress.
Vital signs. Vital signs are stable, and the patient is afebrile, further ruling out an infectious cause. Fever and tachycardia may be suggestive of an infectious process. Tumors can also cause fever either secondary to associated inflammation or infection or be caused by the release of inflammatory mediators, such as tumor necrosis factor.
Maxillofacial. There is a soft, doughy midline swelling of the submandibular area measuring 6 cm in diameter. The mass is freely movable subcutaneously with no clear attachment to the overlying skin. No fluctuance or frank fluid component is appreciated within the mass on bimanual examination. It is not warm to palpation as would be seen with inflammation. The overlying skin appears normal ( Fig. 45.1 ). No palpable cervical adenopathy is noted. Palpable cervical lymphadenopathy may be a harbinger of metastasis or acute or chronic inflammation.
Intraoral. The patient is partially edentulous with no grossly carious dentition noted. There are no soft tissue lesions in the oral cavity. Salivary flow appears normal and without evidence of obstruction or erythema at the orifices of the submandibular and parotid ducts, an important finding that makes sialadenitis unlikely. The muscles of mastication and temporomandibular joints function normally and appear unremarkable on examination. Bimanual intraoral examination also reveals a palpable mass in the midline floor of the mouth that appears to be contiguous with the anterior neck mass. The mass does not elevate with tongue protrusion or swallowing. Elevation of the mass would be consistent with a thyroglossal duct cyst.
Imaging
Imaging plays an important role in the diagnosis of neck lesions. It offers details on the anatomic location of a mass, consistency of the mass, and possible involvement of adjoining anatomic structures. Imaging modalities include Panorex imaging, computed tomography (CT), magnetic resonance imaging, combined positron emission tomography (PET/CT) scans, and ultrasonography. For the pediatric population, ultrasonography is the first-line imaging modality for the evaluation of superficial pediatric masses because of reduced radiation exposure and need for iodinated contrast material. A vast majority of these lesions found in this population ultimately prove to be benign.
Panoramic, lateral cephalometric or lateral neck films are rarely used in evaluating soft tissue neck masses. However, panoramic radiography should be used as a screening tool for evaluation of the dentition if there is suspicion of an odontogenic source of infection. Contrast-enhanced CT scanning is the first line and best imaging for evaluating a neck mass. Contrast-induced acute kidney injury is a feared adverse event when obtaining contrast-enhanced CT imaging. Risks and benefits of this imaging modality should be considered in patients with a compromised kidney function (i.e., estimated glomerular filtration rate <30 mL/min).
Magnetic resonance imaging is indicated for masses requiring further definition of soft tissue such as infiltrative soft tissue masses or suspicion of malignant perineural spread. PET/CT scans play a very limited role in the initial evaluation of a neck mass and are instead more useful in the later evaluation when considering malignancy as well as possible distant metastasis.
For the current patient, the panoramic radiograph demonstrated no source of odontogenic or osseous pathology. The contrast-enhanced CT scan showed a 5-cm, cystic-appearing mass in the anterior midline neck between the mandible and the hyoid bone ( Fig. 45.2 ). Several spherical densities were noted within the lesion. There was no evidence of adenopathy. The mass appeared discrete and not attached to the overlying skin.
Labs
No specific laboratory tests are indicated in the absence of a pertinent medical history. However, in patients in whom the provided history or the physical examination findings are ambiguous, it is suggested that laboratory studies be performed in concurrence with a malignancy work-up in select patients. Most patients should have a complete blood count with differential. For some patients, you may consider an erythrocyte sedimentation rate or C-reactive protein to evaluate for systemic inflammation. A blood culture is helpful for patients who are febrile. Infectious causes such as Epstein-Barr virus, cytomegalovirus, HIV, Toxoplasma gondii infection, brucellosis, and Bartonella infection may be investigated based on an increased index of suspicion.
Differential diagnosis
The differential diagnosis of a neck mass can be quite extensive and can include any or all of the intricate structures in the neck. There are several considerations in distinguishing between inflammatory and infectious causes, anatomic variants, congenital lesions, and benign or malignant processes. One of the most important aspects in assessing a neck mass is a thorough patient history. The age of the patient is an important initial consideration. An adult patient older than 40 years of age has an 80% chance that a nonthyroidal neck mass will be neoplastic; of these, 80% of cases are metastatic squamous cell carcinoma (SCC) from the aerodigestive tract. Fig. 45.3 presents a flowchart for the diagnosis of a neck mass that incorporates age and location as distinguishing factors.
