Your pathology report for squamous cell carcinoma of the larynx

by Jason Wasserman MD PhD FRCPC and Zuzanna Gorski MD FRCPC
November 6, 2025

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Squamous cell carcinoma is the most common type of cancer found in the larynx. The larynx, also known as the voice box, is situated in the neck and plays a crucial role in breathing, swallowing, and speaking. It contains the vocal cords and connects the throat (pharynx) to the trachea (windpipe).

The larynx is divided into three main parts, or subsites:

• Supraglottis – The upper part of the larynx above the vocal cords, which includes the epiglottis and false vocal cords.

• Glottis – The middle part that contains the true vocal cords responsible for sound production.

• Subglottis – The lower part that extends from below the vocal cords to the top of the trachea.

Squamous cell carcinoma of the larynx starts from the squamous cells that line the inner surface of these regions. The location where the cancer begins helps determine its symptoms, treatment, and stage.

What are the symptoms of squamous cell carcinoma?

The symptoms of squamous cell carcinoma vary depending on the part of the larynx affected and the size of the tumour.

Common symptoms include:

• Hoarseness or change in voice that persists for more than two weeks.

• A lump or sensation of fullness in the throat.

• Difficulty swallowing (dysphagia) or pain while swallowing (odynophagia).

• Ear pain that does not come from an ear infection.

• Shortness of breath or noisy breathing if the tumour obstructs the airway.

• Persistent cough or coughing up blood.

• Unexplained weight loss or fatigue.

• A lump in the neck caused by the spread of cancer to the lymph nodes.

Any persistent change in voice or swallowing should be assessed by an ear, nose, and throat (ENT) specialist.

What causes squamous cell carcinoma?

Squamous cell carcinoma of the larynx develops when the squamous cells that line the larynx accumulate genetic damage that allows them to grow uncontrollably.

The major risk factors include tobacco use of any kind and heavy alcohol consumption. These risk factors are also linked to keratinizing squamous dysplasia of the larynx, a precancerous condition that can develop into invasive squamous cell carcinoma over time if left untreated.

Other possible causes include chronic irritation from exposure to chemicals, previous head and neck radiation, and long-standing voice strain. Most squamous cell carcinomas of the larynx are not caused by human papillomavirus (HPV), unlike cancers of the oropharynx (tonsils and base of the tongue), where HPV infection plays a larger role.

How is this diagnosis made?

The diagnosis of squamous cell carcinoma of the larynx is made after a biopsy is examined by a pathologist, a doctor who diagnoses disease by studying tissue under a microscope. The diagnostic process often involves physical examination, imaging studies, and tissue sampling.

Clinical examination

Your doctor begins by examining the larynx with a small mirror or a flexible fiber-optic camera inserted through the nose (laryngoscopy). This allows direct visualization of the vocal cords and surrounding structures. The doctor will assess whether the vocal cords move normally and note any areas that are ulcerated or irregular.

Imaging

Imaging studies, such as CT, MRI, or PET-CT scans, are performed to assess the size of the tumour, whether it has invaded nearby structures, such as cartilage, and if it has spread to lymph nodes or distant organs. These images also help surgeons plan the most appropriate treatment.

Biopsy

A biopsy is required to confirm the diagnosis. This is often done during a procedure called microlaryngoscopy, in which a thin scope is inserted through the mouth under general anesthesia to collect tissue samples. The samples are preserved in fixative and sent to a pathology laboratory for microscopic evaluation by a pathologist.

Microscopic examination

Under the microscope, the pathologist looks for abnormal squamous cells that have invaded beyond the epithelium (surface lining) into the tissue below. When this occurs, the condition is described as invasive squamous cell carcinoma.

If the sample is a small biopsy, the pathologist can confirm the presence of invasive carcinoma, describe the appearance of the tumour cells, and assign a preliminary histologic grade. Some features, such as whether cancer has invaded cartilage or spread along nerves or blood vessels, may not be visible in a small biopsy and can only be fully assessed once the entire tumour is removed.

If the larynx or part of it is surgically removed, the pathologist examines the entire specimen in detail. The resection report describes the tumour’s size, precise location, histologic grade, extent of spread (tumour extension), and whether perineural invasion, lymphovascular invasion, or invasion of bone or cartilage is present. The report also includes an evaluation of surgical margins and lymph nodes removed during neck dissection.

Histologic grade

Histologic grade describes how much the tumour cells differ from normal squamous cells and how much keratin (a structural protein made by squamous cells) they produce.

• Well-differentiated tumours resemble normal squamous cells and usually produce keratin. These cancers tend to grow more slowly.

• Moderately differentiated tumours have cells that look less like normal squamous cells, form less keratin, and invade more deeply into surrounding tissue.

• Poorly differentiated tumours look very abnormal and produce little or no keratin. They are usually more aggressive and more likely to spread.

The histologic grade provides important information about how the tumour behaves and is included in your pathology report.

Tumour extension

Tumour extension describes how far the cancer has spread from its starting point inside the larynx into surrounding structures.

Squamous cell carcinoma of the larynx begins in the epithelium (inner lining) of the larynx. The epithelium forms the surface that covers the vocal cords and the inside of the voice box. As the tumour grows, it can extend into deeper layers of tissue and spread beyond the larynx.

Depending on the tumour’s site and size, cancer may invade nearby structures such as the thyroid cartilage (the main cartilage that forms the front of the voice box), cricoid cartilage (a ring-shaped cartilage below the thyroid cartilage), the thyroid gland, esophagus, or soft tissues of the neck.

Tumour extension is important because once the cancer grows through cartilage or into adjacent organs, it is considered a higher stage (T4). These findings have major implications for both treatment and prognosis, as more extensive tumours may require total laryngectomy (removal of the voice box) and combined therapy with radiation or chemotherapy.

Perineural invasion

Perineural invasion (PNI) means cancer cells are growing along or around a nerve. Nerves are small structures that carry sensation and control movement. When tumour cells travel along nerves, they can spread further from the primary tumour site. Perineural invasion is considered an aggressive feature because it increases the risk that the cancer may come back after treatment or spread to nearby tissues.

Pathologists identify perineural invasion by observing tumour cells surrounding or infiltrating a nerve under the microscope.

Lymphovascular invasion

Lymphovascular invasion (LVI) means cancer cells are found inside lymphatic channels or blood vessels near the tumour. Lymphatic channels transport fluid and immune cells, while blood vessels transport blood throughout the body. The presence of cancer cells in these channels increases the risk of spread to lymph nodes in the neck or to distant organs. Pathologists may use special stains to confirm the presence of tumour cells within vessels.

Margins

Margins refer to the edges of tissue removed during surgery. After removal, the pathologist inks the specimen and examines it under the microscope to see how close the tumour comes to the edge.

A margin is considered negative when no cancer cells are visible at the edge, indicating that the tumour was completely removed. A margin is positive when cancer cells are present at the edge, indicating that some tumour may remain. Some reports use the term close margin when tumour cells are within a few millimeters of the edge.

Margins are described as mucosal (surface), deep soft tissue, and cartilage margins. Positive or close margins may lead to recommendations for additional surgery or radiation therapy.

Lymph nodes

Lymph nodes are small, bean-shaped immune organs found throughout the body. They filter fluid and trap bacteria, viruses, and cancer cells. The larynx drains into lymph nodes located on both sides of the neck, which are divided into levels (I through VI).

Because squamous cell carcinoma of the larynx can spread to these nodes, surgeons often perform a neck dissection during surgery. In this procedure, lymph nodes from one or both sides of the neck are removed and sent to the pathology laboratory.

The pathologist examines each node under the microscope to see if cancer cells are present. The report lists the number of lymph nodes examined, the number that contain cancer, the size of the largest tumour deposit, and whether there is extranodal extension, which means the cancer has grown through the outer capsule of a lymph node into surrounding tissue.

Lymph node involvement is an important part of staging and helps doctors decide whether postoperative radiation or chemotherapy should be added to reduce the risk of recurrence.

PD-L1

PD-L1 is a protein that allows tumour cells to hide from the immune system. PD-L1 testing may be performed in patients with advanced, recurrent, or metastatic squamous cell carcinoma of the larynx to help identify those who may benefit from immunotherapy.

The test result is reported as a Combined Positive Score (CPS), which measures PD-L1 expression on both tumour cells and immune cells. A higher CPS score may indicate that the cancer is more likely to respond to immunotherapy drugs such as pembrolizumab.

Pathologic stage

The pathologic stage for squamous cell carcinoma of the larynx is based on the TNM staging system, an internationally recognized system created by the American Joint Committee on Cancer. This system uses information about the primary tumour (T), lymph nodes (N), and distant metastatic disease (M) to determine the complete pathologic stage (pTNM). Your pathologist will examine the submitted tissue and assign a number to each part. Generally, a higher number indicates a more advanced disease and a poorer prognosis.

Tumour stage (pT)

There are three different tumour staging systems for squamous cell carcinoma of the larynx. The system selected depends on where in the larynx the tumour started.

Supraglottic tumours

• T1 – The tumour has not spread beyond the supraglottis, and the vocal cords move normally.
• T2 – The tumour has spread beyond the supraglottis to another section of the larynx or the tissue just outside the larynx.
• T3 – The vocal cords no longer move normally, or the tumour has spread to tissues further away from the larynx.
• T4 – The tumour has spread to the muscles of the tongue, muscles at the front of the neck, the spine, and the chest, or has gone through the cartilage that sits in front of the thyroid gland.

Glottic tumours

• T1 – The tumour only involves the vocal cords.
• T2 – The tumour has spread beyond the glottis to involve the supraglottis or subglottis, or the vocal cords no longer move normally.
• T3 – The vocal cords no longer move normally, or the tumour has spread to the tissue just outside of the larynx.
• T4 – The tumour has spread to the muscles of the tongue, muscles at the front of the neck, the spine, and the chest, or has gone through the cartilage that sits in front of the thyroid gland.

Subglottic tumours

• T1 – The tumour only involves the subglottis.
• T2 – The tumour has spread to the vocal cords.
• T3 – The vocal cords no longer move normally, or the tumour has spread to the tissue just outside of the larynx.
• T4 – The tumour has spread to the muscles of the tongue, muscles at the front of the neck, the spine, and the chest, or has gone through the cartilage that sits in front of the thyroid gland.

Nodal stage (pN)

Squamous cell carcinoma of the larynx is given a nodal stage between 0 and 3 based on the examination of all lymph nodes received. Both N2 and N3 are further divided into sub-stages (for example, N2a, N2b, etc).

The following four features are used to determine the nodal stage:

• The number of lymph nodes that contain cancer cells.

• The size of the largest tumour deposit.

• Extranodal extension.

• Whether the lymph nodes with cancer cells are on the same or opposite side of the neck as the primary tumour.

Using these features, your pathologist will provide a nodal stage as follows:

• NX – No lymph nodes were sent for pathologic examination.
• N0 – No cancer cells are seen in any lymph nodes examined.
• N1 – Cancer cells are found in only one lymph node. The lymph node with cancer cells is on the same side as the tumour (ipsilateral), the tumour deposit measures 3 cm or less in size, and extranodal extension is not seen.
• N2a – There are two possible options for N2a stage disease:

  • Cancer cells are found in only one lymph node. The lymph node with cancer cells is on the same side of the tumour (ipsilateral), the tumour deposit measures 3 cm or less, and extranodal extension is seen.

  • Cancer cells are found in only one lymph node. The lymph node with cancer cells is on the same side of the tumour (ipsilateral). The tumour deposit measures more than 3 cm but not more than 6 cm, and extranodal extension is not observed.
• N2b – Cancer cells are found in more than one lymph node. All lymph nodes with cancer cells are located on the same side as the tumour (ipsilateral), none of the tumour deposits exceed 6 cm in size, and extranodal extension is not observed.
• N2c – Cancer cells are found in one or more lymph nodes. At least one of the lymph nodes with cancer cells is located on the opposite side of the tumour (contralateral), none of the tumour deposits are more than 6 cm in size, and extranodal extension is not observed.
• N3a – Cancer cells are found in at least one lymph node on the same (ipsilateral) or opposite side of the tumour (contralateral). The largest tumour deposit is more than 6 cm in size, and extranodal extension is not seen.
• N3b – There are three possible options for N3b stage disease:
  • Cancer cells are found in only one lymph node. The lymph node with cancer cells is on the same side of the tumour (ipsilateral), the tumour deposit measures more than 3 cm and extranodal extension is seen.
  • Cancer cells are found in more than one lymph node, and extranodal extension is seen in at least one lymph node.
  • Cancer cells are found in only one lymph node. The lymph node with cancer cells is located on the opposite side of the tumour, and extranodal extension is seen.

What happens after the diagnosis?

After diagnosis, your healthcare team reviews your pathology report, imaging results, and overall health to plan the most effective treatment. The team typically includes an ear, nose, and throat (ENT) surgeon, a radiation oncologist, a medical oncologist, and a pathologist.

For most patients, surgery is the primary treatment. Depending on the tumour’s size and location, surgery may involve removing part or all of the larynx. Lymph nodes in the neck are also removed and examined for abnormalities.

If the tumour has high-risk features such as perineural invasion, lymphovascular invasion, positive or close margins, extranodal extension, or extensive tumour extension, additional treatment with radiation or combined chemoradiation may be recommended.

For recurrent, metastatic, or unresectable cancer, systemic therapies such as chemotherapy, radiation therapy, or immunotherapy (guided by PD-L1 testing) may be offered.

After treatment, patients are followed closely with regular examinations and periodic imaging to monitor for recurrence. Speech, swallowing, and nutrition support are essential parts of recovery. Smoking cessation, alcohol reduction, and ongoing dental and medical care help lower the risk of recurrence and improve long-term outcomes.

Questions for your doctor

• In which part of my larynx did the tumour start?

• What did the pathology report say about tumour extension?

• Did the report mention perineural invasion or lymphovascular invasion?

• Were the surgical margins clear of cancer?

• How many lymph nodes were removed, and did any contain cancer or show extranodal extension?

• What is my pathologic stage (pT and pN categories)?

• Was PD-L1 testing performed, and could immunotherapy be an option for me?

• What treatments do you recommend, and what side effects should I expect?

• How will my speech, swallowing, and breathing be managed during and after treatment?

• What is the plan for follow-up visits and imaging studies?