Insights on Extranodal Extension in Head and Neck Cancers

Christina Henson, MD, radiation oncologist at the University of Oklahoma, discussed some of the current imaging guidelines in head and neck cancer, with a focus on extranodal extension.

According to the National Comprehensive Cancer Network (NCCN) guidelines, extranodal extension should not be clinically diagnosed solely based on imaging unless accompanied by major, obvious clinical signs, such as a fixed neck mass tethered to muscle or bone or significant nerve dysfunction. While most patients undergo CT and PET scans before treatment, subtle cases of extranodal extension often remain undiagnosed until surgery, as current protocols emphasize clinical findings over imaging for diagnosis.

In thyroid cancer, particularly papillary thyroid carcinoma, lymph node metastases are common, and extranodal extension can influence prognosis and treatment decisions. The challenges in diagnosing subtle extranodal extension in other head and neck cancers mirror those in thyroid cancer, where imaging may not always reveal the full extent of disease.

Transcription:

0:10 | Most patients with head and neck cancer are going to get a CT scan and usually a PET scan before they start treatment for staging. Right now, the focus of [our] paper is on a specific finding on imaging, which is extranodal extension. The way that the NCCN guidelines are written, and the way that they are practiced at most centers that follow the NCCN guidelines, is that a clinical diagnosis of extranodal extension is not supposed to be made in the absence of major, obvious clinical findings.

0:46 | But you would not need imaging to diagnose a fixed mass in the neck that is tethered to muscle or bone or is causing major nerve dysfunction. Right now, we are only supposed to call extranodal extension on imaging if 1 of those other clinical findings is present as well. The more subtle cases, which is a much larger proportion of the cases, go undiagnosed until surgery.