How is Head and Neck Cancer Diagnosed?

This is the sixth page in the Understanding Head and Neck Cancer Guide. This guide was developed by the HealthTree Education Team and was last updated and reviewed on May 22, 2026.

If your doctor or dentist thinks you may have head and neck cancer, there are several tests and procedures that can confirm a diagnosis. Diagnosis relies on a combination of your symptoms, a physical examination, imaging, and ultimately a tissue sample examined under a microscope.

This page lists all of the different tests that may be needed. Some are used to confirm a head and neck cancer diagnosis. Others are used to learn more about the cancer, such as whether it has spread, and can help guide treatment. Some of these tests may also be used to monitor how well treatment is working. You may not have all of the tests on this list.

Talk to your care team if you have questions about which tests you received and what the results mean for your diagnosis.

Physical examination

Your doctor will typically begin with a thorough medical history and a physical examination, including a careful inspection of the mouth, throat, and neck. The exam includes looking inside the mouth with a light and a mirror, feeling the tongue and inside of the cheeks, and palpating the neck for any lumps or enlarged lymph nodes.

Endoscopy

Endoscopy uses a thin, flexible tube with a camera to see areas that cannot be seen with the naked eye:

• Nasendoscopy or fiberoptic laryngoscopy. A thin scope is passed through the nose to look at the back of the nose, throat, and voice box. This is usually done in the office with local anesthetic spray.
• Panendoscopy (examination under anesthesia). A more thorough endoscopic examination of the upper airway and digestive tract, performed in the operating room under general anesthesia. It allows the surgeon to fully assess the primary tumor and take biopsies.

Imaging tests to diagnose head and neck cancer

Imaging tests create pictures of the inside of the body and are used to define the extent of the tumor and check whether head and neck cancer has spread:

• Computed tomography (CT). A CT scan of the head, neck, and chest is commonly used to evaluate the size and extent of the primary tumor and check for spread to lymph nodes and the lungs.
• Magnetic resonance imaging (MRI). Particularly useful for evaluating soft tissue, the tongue, and the base of the skull. MRI is often used for cancers of the oropharynx, nasopharynx, and salivary glands.
• PET-CT (positron emission tomography). Combines a metabolic scan with a CT scan to find areas of high cancer cell activity. Often used to evaluate advanced disease, look for distant spread, and assess response after treatment.
• Ultrasound. May be used to evaluate lymph nodes in the neck or guide a needle biopsy.
• Chest X-ray or CT chest. Used to check whether cancer has spread to the lungs, which is the most common site of distant metastasis.
• Dental imaging. A dental evaluation, often including a panoramic X-ray, is typically performed before radiation therapy to identify and address any dental problems.

Biopsy

A definitive diagnosis of head and neck cancer always requires a tissue sample, called a biopsy. The type of biopsy depends on the location of the tumor:

• Incisional or excisional biopsy. A surgeon removes a small piece of the tumor (incisional) or, for small lesions, the entire lesion (excisional). This is the standard biopsy method for visible mouth and throat lesions.
• Fine needle aspiration (FNA). A thin needle is used to draw out cells from a neck lump or salivary gland mass. FNA is often the first test used for a neck mass of unknown cause.
• Core needle biopsy. A larger needle is used to take a small tissue sample, sometimes used when FNA does not give enough information.
• Endoscopic biopsy. Performed during endoscopy or panendoscopy under general anesthesia, particularly for tumors of the throat, voice box, or nasopharynx.

A pathologist then analyzes the tissue sample to confirm cancer, identify the type (squamous cell carcinoma, salivary gland cancer, etc.) and subtype, and determine the grade. A pathologist is a doctor who specializes in examining tissue samples.

HPV and EBV testing

For cancers of the oropharynx, the tumor is tested for the presence of HPV, most commonly using a test called p16 immunohistochemistry. HPV status is now a key factor in staging and treatment planning for oropharyngeal cancer. For cancers of the nasopharynx, the tumor or a blood test may be used to check for Epstein-Barr virus (EBV).

Biomarker and genetic tests

Molecular testing is an increasingly important part of head and neck cancer care. Results help guide treatment decisions:

• p16/HPV testing. All oropharyngeal cancers should be tested for p16 (a marker of HPV-related cancer). HPV status affects staging, treatment decisions, and prognosis.
• EBV testing. For nasopharyngeal cancer, EBV-DNA testing in the blood is used both to help with diagnosis and to monitor treatment response.
• PD-L1 testing. Measures the level of a protein called PD-L1 in the tumor. PD-L1 expression helps determine whether immunotherapy may be effective.
• Comprehensive tumor profiling. For recurrent or metastatic disease, broader tumor profiling can look for mutations in genes such as NTRK, EGFR, and others that may guide use of targeted therapies.

Blood Tests

Blood tests are not used to diagnose head and neck cancer directly, but they help evaluate overall health and organ function before treatment:

• Complete blood count (CBC) and comprehensive metabolic panel. Check overall health, kidney and liver function, which can be affected by cancer or its treatment.
• EBV-DNA blood test. Used in nasopharyngeal cancer for diagnosis, prognosis, and monitoring.
• Thyroid function tests. Often checked before and after radiation to the neck, since radiation can affect the thyroid gland.

Dental and nutrition evaluation

Before treatment begins, most patients undergo a dental evaluation and a nutritional assessment. Dental problems are addressed before radiation therapy to lower the risk of complications. A speech and swallowing evaluation may also be performed to establish a baseline and plan supportive therapy.