Imaging description

Squamous cell cancer (SCC) arising from the upper aerodigestive tract is common, and the first clinical presentation of SCC is a palpable neck mass in more than 30% of the cases as a result of metastatic nodes. Palpable neck mass often leads to CT or MRI, which show enlarged lymph node(s) and sometimes the primary mass in the pharynx or larynx. Most metastatic nodes are solid and show varying degrees of central fluid attenuation or signal due to necrosis, particularly when they are larger than 3cm.

A nodal metastasis that is completely or mostly cystic is a phenomenon seen with increasing frequency secondary to increase in human papilloma virus (HPV)-related SCC of the neck (Figs. 78.1, 78.2) [1]. HPV-related SCC has a tendency to involve the oropharynx, and currently the majority of oropharyngeal SCC is secondary not to smoking but to HPV infection, which occurs in younger individuals who often lack the typical history associated with SCC of the neck, i.e., smoking and alcohol abuse. Clinicians and radiologists who are less familiar with this phenomenon may not be as concerned with the possibility of cancer in patients presenting with a cystic neck mass, and may consider congenital cystic masses such as branchial cleft cysts or lymphatic malformations as the likely etiology. To compound matters further, these cystic metastatic nodes may not have any appreciable FDG uptake on PET studies due to their cystic nature. Adult patients presenting with cystic neck masses should appropriately be worked up for the presumptive diagnosis of SCC of the pharynx.