Man With Persistent Neck Swelling

About 1 month ago, a 58-year-old man experienced malaiseand fatigue accompanied by mild diffuse swelling in his neck.After 3 days, the malaise and fatigue began to abate. They resolvedafter a week; however, minimal swelling on the left sideof the neck remains. The patient has no other symptoms.

Two years earlier, squamous cell carcinoma of the larynxwas diagnosed; the tumor was excised and radiation therapygiven. The rest of his medical history is unremarkable. Hesmokes a pack of cigarettes daily and drinks alcohol socially.

The patient is slightly overweight. Temperature is 37.2^oC(99^oF); heart rate, 92 beats per minute; respiration rate, 18breaths per minute; and blood pressure, 138/92 mm Hg.Heart and lungs are normal, as is the oral cavity. Examinationof the neck reveals mild fullness without significant tendernesson the left side at the level of the mandible, along the jugularchain of lymph nodes; inferior extension may be present.

Figure 1

Figure 2

A CT scan is ordered to evaluate the soft tissues of theneck. Although the CT images obtained before the patient'ssurgery 2 years earlier are not available, the radiologic reportdescribes minimal fullness of the larynx on the left side (thesite of the primary tumor) and no evidence of adenopathy.

New CT images at the level of the mandible and at thelevel of the submandibular glands reveal prominent lymph nodeslateral to the left internal jugular vein and posterior to the vesselsdeep to the left sternocleidomastoid muscle (Figure 1).These lymph nodes measure less than 1 cm in short axis; 1 cmor greater is the CT criterion for designating a lymph node abnormal.However, the patient's nodes demonstrate decreasedcentral density-especially the node in the posterior triangle.

Which diagnostic test would you order next and why?

WHICH TEST-AND WHY: A positron emission tomography(PET) scan is the best test to determine whether thetumor has recurred and, if it has, to assess the extent ofdisease. Because the patient currently has no symptomsother than mild neck swelling, the key concern is recurrenceof the squamous cell carcinoma of the neck. Decreasedcentral density on CT suggests more activepathology than a node with homogeneous soft tissuedensity.

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Figure 4

Results of the PET scan. Axial images at the levelof the mandible and at the level of the submandibularglands show dramatically increased activity in the regionof the prominent lymph nodes-and no evidence of otherdisease (Figure 2, A and B). The 2 abnormal nodes canalso be seen on a left parasagittal image (Figure 2, C).

PET is highly useful in evaluating patients for recurrentsquamous cell carcinoma of the head and neck. A recentsurvey of the literature showed that the sensitivityand specificity of PET in this setting are 98% and 83%, respectively,while the sensitivity and specificity of CT are54% and 74%.¹ PET has greater sensitivity because it canoften show whether lymph nodes less than 1 cm in shortaxis are abnormal. The study has greater specificity becauseit can show whether lymph nodes larger than 1 cmare free of disease; such lymph nodes most likely representprevious disease that is now quiescent.

In addition, a PET scan is a whole body scan; thus, itcan image the chest, abdomen, and pelvis-as well as thehead and neck-in one sitting. This makes it possible todetect sites of metastatic disease that would be excludedin a CT scan of the neck.

Outcome of this case. The patient was referred toan otolaryngologist, and radical neck dissection was performed.The 2 enlarged lymph nodes demonstrated recurrenceof disease; the remainder of the neck was free of disease.At 6-month follow-up, the patient was doing well.

References:

REFERENCE:1. Gambhir SS, Czernin J, Schwimmer J, et al. A tabulated summary of theFDG PET literature. J Nucl Med. 2001;42(suppl 5):1S-93S.