Lymph nodes in the neck can grow in size for a number of reasons including noncancerous causes such as an infection or inflammation in the head and neck. However, enlarged lymph nodes that have been present for greater than 2 weeks, especially in patients at potential risk for cancer, should be further investigated with imaging, potentially a biopsy, and referral to a specialist.
Imaging
Imaging scans, also known as radiologic studies, provide the doctor with an inside view of the body. Imaging of the head and neck will be required to determine the extent as well as the behavior of a growth, and is a vital step prior to treatment of any tumor in the neck. There are multiple types of imaging modalities that can be used to evaluate enlarged or suspicious lymph nodes in the neck. One of the most common initial imaging tests is an ultrasound of the neck. If a cancerous or metastatic node is suspected, then further evaluation with cross-sectional imaging, such as a CT or an MRI scan will be performed. A more advanced imaging study called a PET/CT may also be helpful in determining whether lymph nodes in the neck are likely to harbor cancer cells and can be useful in finding a primary tumor from which these cancer cells originated. Learn more about imaging and radiology.
Biopsy
A biopsy is the removal of a small piece of tissue to examine under a microscope to see if it is cancerous. A biopsy of a suspicious lump in the neck is usually needed prior to treatment. In the vast majority of cases, a fine needle aspiration (FNA) biopsy will be performed to sample any suspicious lymph nodes in the neck. The doctor performing the biopsy may use ultrasound or CT scan to guide the procedure. Sometimes, an FNA biopsy is unable to make a definitive diagnosis, and other types of biopsy are needed, such as a core-needle biopsy, an open incisional biopsy, or an excisional biopsy. Samples from lymph node biopsies may be tested for HPV, P16, and EBV to help determine the site of origin of the tumor. Learn more about FNA and other kinds of biopsies.
Unknown (Occult) Primary
In some situations, doctors find lymph nodes in the neck which contain cancer, but initial physical exam and imaging scans are unable to locate the main (primary) tumor that led to the spread of cancer to those lymph nodes. This is called an unknown or occult primary. Occult simply means hidden. In these situations, further evaluation may be needed. This could include more advanced imaging (PET/CT scan) and/or evaluation with an endoscopy in the operating room. The most common cancer that presents as an unknown primary is squamous cell carcinoma, and the most common location of the primary tumor is in the tonsils or the base of the tongue.
