Spindle Cell Squamous Cell Carcinoma of the Larynx: Understanding Your Pathology Report

Section Editor: Jason Wasserman MD PhD FRCPC
July 26, 2026

Spindle cell squamous cell carcinoma is a rare type of squamous cell carcinoma of the larynx (voice box). You may also see it called sarcomatoid squamous cell carcinoma. It is named for the shape of its cells: instead of the rounded cells seen in ordinary squamous cell carcinoma, the cancer cells are long and thin, or spindle-shaped.

That unusual shape matters because it makes this tumor look like a sarcoma, a completely different kind of cancer that starts in connective tissue and is treated differently. Despite the resemblance, spindle cell squamous cell carcinoma arises from the squamous cells lining the larynx. Laboratory tests called immunohistochemistry are used to tell the two apart, and confirming which one you have is one of the most important steps in making this diagnosis.

This tumor most often begins on or near the vocal cords, though it can start anywhere in the larynx. Compared with ordinary squamous cell carcinoma of the larynx, it tends to grow more quickly and return more often after treatment, which is why it is treated with particular care.

This article explains the findings you are likely to see on a pathology report for spindle cell squamous cell carcinoma of the larynx, what each one means, and why it matters for your care.

What causes spindle cell squamous cell carcinoma of the larynx?

Like ordinary squamous cell carcinoma of the larynx, spindle cell squamous cell carcinoma develops when the squamous cells lining the larynx are damaged repeatedly over many years, until enough errors build up in their genetic material that the cells grow without normal control. The main causes are:

Tobacco. The most important risk factor, in any form.
Alcohol. Heavy use raises risk on its own, and combining it with smoking raises risk substantially more.
Previous radiation to the head and neck. This carries particular weight for this tumor type. A higher proportion of spindle cell squamous cell carcinomas arise in an area that was treated with radiation years earlier than is the case for ordinary laryngeal squamous cell carcinoma.
Workplace exposures. Long-term exposure to certain chemicals, dusts, or fumes may also contribute.

Many of these tumors develop from or alongside keratinizing squamous dysplasia, also called high grade dysplasia of the larynx, a precancerous change in which abnormal squamous cells build up in the surface lining before becoming invasive cancer.

What are the symptoms of spindle cell squamous cell carcinoma of the larynx?

Because spindle cell squamous cell carcinoma most often arises on or near the vocal cords, the most common first symptom is hoarseness, meaning a change in the voice that may sound scratchy, strained, or rough. Other symptoms may include:

A feeling of fullness or a lump in the throat
Difficulty or pain with swallowing
Shortness of breath or noisy breathing if the tumor narrows the airway
Ear pain on one side
A lump in the neck, which may mean the cancer has spread to a lymph node

Any change in the voice lasting more than two weeks should be assessed by an ear, nose, and throat specialist.

How is the diagnosis made?

The diagnosis of spindle cell squamous cell carcinoma of the larynx is made when a pathologist examines a tissue sample under the microscope. The sample is obtained by biopsy during a procedure called microlaryngoscopy, in which a thin scope is passed through the mouth under general anesthetic so the surgeon can see the larynx directly and take samples.

Under the microscope, the tumor is made up of spindle cells, long thin cells with tapered ends and enlarged, irregular nuclei. Your report may describe them as pleomorphic, meaning they vary considerably in size and shape from one another. Some tumors also contain areas of ordinary-looking squamous cell carcinoma alongside the spindle cells, and finding those areas helps confirm the diagnosis. Because the spindle cells closely resemble a sarcoma, immunohistochemistry is routinely performed to establish that they are squamous in origin. Those results are described in the next section. Once the diagnosis is confirmed, imaging such as a CT scan or MRI of the neck, and PET-CT for more advanced disease, shows how far the tumor extends and whether lymph nodes are involved.

Immunohistochemistry

Immunohistochemistry uses antibodies to detect specific proteins inside the tumor cells. For this diagnosis, it does something essential: it establishes whether the spindle cells came from the squamous lining of the larynx, which makes the tumor a carcinoma, or from connective tissue, which would make it a sarcoma. Because these two cancers are treated very differently, this testing is not a formality. The results appear on your pathology report as a list of markers, each reported as positive or negative. The markers most often used are:

Pan-cytokeratin (AE1/AE3): positive. Cytokeratins are proteins found in cells that form linings, so a positive result confirms the tumor arises from the lining rather than from connective tissue. In spindle cell tumors, this staining can be weak or patchy, so a negative or only focal result does not rule out the diagnosis.
p63 and p40: positive. Markers of squamous cells found in the nucleus. These are often more reliably positive in the spindle cell areas than the cytokeratins are, so they carry particular weight here.
CAM5.2: positive. Another cytokeratin marker that may be added when the AE1/AE3 result is weak.
Sarcoma markers: negative. Markers used to identify true sarcomas are typically absent. A negative result on these supports the diagnosis of a carcinoma rather than a sarcoma.

Not every case needs every marker, so a report listing only some of them is not incomplete. A positive result on any of the squamous markers, even a patchy one, taken together with the appearance of the tumor, confirms spindle cell squamous cell carcinoma rather than a sarcoma.

Is spindle cell squamous cell carcinoma given a histologic grade?

Usually not in the same way as ordinary squamous cell carcinoma. Spindle cell squamous cell carcinoma is not typically assigned a grade of well, moderately, or poorly differentiated, because by its nature this tumor is regarded as high grade. The spindle-shaped, markedly variable cells that define it already indicate a high degree of abnormality.

Your report may state directly that the tumor is high grade, or it may describe the degree of variation between the cells and the number of cells actively dividing, called the mitotic count, as a measure of how quickly the tumor is growing. If you are looking for a well, moderate, or poor grade on your report and cannot find one, nothing has been left out.

Tumor extension into nearby structures

Your report will describe how far the cancer has grown from where it started. Spindle cell squamous cell carcinoma begins in the epithelium, the inner lining of the larynx, and can grow into the deeper layers of the laryngeal wall, into the cartilage that forms the framework of the voice box, or beyond the larynx into the thyroid gland, the windpipe, the esophagus, or the soft tissues of the neck.

When the tumor spreads from one region of the larynx into a neighboring one, for example from the vocal cords upward or downward, this is called transglottic extension and raises the tumor stage. Your report or your surgeon will also describe whether the vocal cords still move normally. A cord that has stopped moving, described as fixed, indicates the tumor has grown into the muscles that move it, and this raises the stage even when the cartilage is not involved. Tumors that remain confined to the larynx are less likely to reach the lymph nodes or return after surgery than those that have grown beyond it.

Perineural invasion

Perineural invasion means cancer cells are growing along or around a nerve. Nerves provide a path that cancer cells can follow beyond the visible edge of the tumor. Your report will state whether perineural invasion is present or absent. When present, it is associated with a higher chance of the cancer returning at the original site, and it is one of the findings the treatment team weighs when considering radiation after surgery.

Lymphovascular invasion

Lymphovascular invasion means cancer cells have entered a small blood vessel or lymphatic channel near the tumor. These vessels can carry cancer cells to the lymph nodes or, less often, to distant organs. Your report will state whether it is present or absent, and when present, it points to a higher chance that cancer cells have spread beyond the tumor.

Surgical margins

Margins are the cut edges of the tissue removed during surgery. The pathologist inks these edges and examines how close the tumor comes to each one.

Negative (clear) margin. No cancer cells at the inked edge. This suggests the tumor was removed completely.
Close margin. Cancer cells come within a few millimeters of the edge without reaching it. This raises the chance of the cancer returning at the same site.
Positive (involved) margin. Cancer reaches the inked edge, meaning some may remain. This is one of the main reasons the treatment team considers further surgery or radiation.

Margins in the larynx are reported separately by location: the mucosal margins at the surface lining, the deep soft tissue margin, and, when cartilage has been removed, the cartilage margin.

Lymph nodes

Lymph nodes are small immune organs that filter fluid draining from the tissues. Squamous cell carcinoma of the larynx can spread to the lymph nodes in the neck, so a neck dissection to remove a group of these nodes is often performed as part of surgery. The pathologist examines each node and reports:

How many lymph nodes were examined and how many contained cancer. Usually written as a ratio, such as 1 of 24. The risk of the cancer returning rises with the number of involved nodes.
The size of the largest deposit of cancer. Measured in millimeters.
Extranodal extension. This means cancer cells have broken through the outer capsule of a lymph node into the surrounding tissue. It is one of the most important adverse findings on the report and is among the findings most likely to lead the treatment team to recommend chemotherapy given together with radiation after surgery.

If no cancer is found in any lymph node, your report will say so. This is a favorable finding.

PD-L1

PD-L1 is a protein that some cancer cells display on their surface to avoid being attacked by the immune system. Immunotherapy drugs called checkpoint inhibitors, such as pembrolizumab (Keytruda) and nivolumab (Opdivo), block this signal so the immune system can recognize and attack the cancer.

PD-L1 testing is not needed to make the diagnosis. It is generally performed when the cancer cannot be removed by surgery, has returned after treatment, or has spread to distant parts of the body. The result is reported as a Combined Positive Score, or CPS, a number that reflects how many cells in and around the tumor show PD-L1. A CPS of less than 1 is considered negative. A CPS of 1 or higher is considered positive and means immunotherapy may be an option, and a higher score suggests the cancer is more likely to respond. Your report will give the specific number. You can read more in the article on PD-L1 testing in cancer.

Pathologic stage (pTNM)

The pathologic stage describes how far the cancer has spread, based on the tissue examined under the microscope. It uses the TNM system, which has three parts: T for the size and extent of the primary tumor, N for spread to the lymph nodes in the neck, and M for spread (metastasis) to more distant parts of the body. The letter “p” in front, as in pT and pN, means the stage was determined by examining tissue rather than by imaging alone. Spindle cell squamous cell carcinoma is staged using the same system as ordinary squamous cell carcinoma of the larynx.

Tumor stage (pT)

The exact criteria for the T category depend on which part of the larynx the cancer started in, because each region has different boundaries. The general pattern is the same across all three, based on how far the tumor has spread within and beyond the larynx and whether the vocal cords still move.

pT1. Tumor confined to one part of the larynx, with the vocal cords moving normally. For cancers of the vocal cords, your report may specify pT1a if one cord is involved or pT1b if both are.
pT2. Tumor has extended into a neighboring part of the larynx or an adjacent area, or vocal cord movement is reduced.
pT3. Tumor is still confined to the larynx but a vocal cord has stopped moving, or the tumor has grown into certain deeper spaces or the inner surface of the thyroid cartilage.
pT4a. Tumor has grown through the cartilage or beyond the larynx into nearby structures such as the windpipe, the thyroid gland, the esophagus, or the soft tissues of the neck.
pT4b. Tumor has grown into deeper structures such as the space in front of the spine, or surrounds the carotid artery. These tumors usually cannot be removed completely by surgery.

Nodal stage (pN)

pN0. No cancer found in any lymph node.
pN1. Cancer in a single lymph node on the same side as the tumor, 3 cm or smaller, without extranodal extension.
pN2. Cancer in a larger node, in more than one node, or in nodes on both sides of the neck, in ways set out by the staging system. This category also includes a single small node on the same side that shows extranodal extension.
pN3. Cancer in a node larger than 6 cm, or extranodal extension in any node beyond the situation covered by pN2.

Your report may not include the M category, because spread to distant parts of the body is usually determined by imaging rather than by the pathologist. Your treatment team combines the pathology findings with your scans to arrive at the overall stage. You can read more in the article on TNM staging.

What is the prognosis for spindle cell squamous cell carcinoma of the larynx?

Prognosis means the likely course and outcome of a disease. Spindle cell squamous cell carcinoma of the larynx returns after treatment more often than ordinary squamous cell carcinoma of the larynx, and in some published series it spreads to distant organs more often as well. The outlook is therefore generally less favorable.

That said, outcome depends heavily on the stage at diagnosis. Tumors found early and removed completely can do well, and because these tumors often arise on the vocal cords, hoarseness may bring them to attention while they are still small. Because this tumor is rare, the available figures come from small groups of patients, so they describe general patterns rather than predicting what will happen for any one person.

The findings on your report associated with a higher risk of the cancer returning are:

Positive or close margins. Strongly associated with the cancer returning at the original site.
Extranodal extension. One of the strongest adverse findings, and a common reason for adding chemotherapy to radiation after surgery.
Perineural invasion. Associated with a higher rate of the cancer returning locally.
Tumor growth beyond the larynx. Reflects more extensive disease and a greater chance of recurrence.
Lymph node involvement. Risk rises with the number of involved nodes.
A tumor arising in a previously irradiated area. These tend to be more difficult to treat, partly because radiation cannot usually be given again to the same area.

One factor is within your control. Continuing to smoke after treatment is associated with higher rates of the cancer returning and with a greater risk of a second, separate cancer developing in the head, neck, or lungs. Support for stopping tobacco is a standard part of care and worth asking for.

What happens after the diagnosis?

After the diagnosis is confirmed, your pathology report is reviewed together with your imaging and overall health, usually by a team that includes ear nose and throat surgeons, radiation oncologists, medical oncologists, and pathologists. The report does not decide treatment on its own, but several of its findings shape the options the team will discuss with you.

Surgery to remove the tumor is the main treatment for most patients, and depending on the size and location this may mean removing part of the larynx or, in some cases, the whole larynx in an operation called a total laryngectomy, which permanently changes how you breathe and speak. Lymph nodes in the neck are usually removed at the same time. Because this tumor returns more often than ordinary squamous cell carcinoma, radiation after surgery is frequently discussed even for earlier-stage disease. When the report shows findings such as positive or close margins, extranodal extension, perineural invasion, or several involved lymph nodes, radiation combined with chemotherapy may be considered. For cancer that has returned or spread, options include chemotherapy, the targeted drug cetuximab, and immunotherapy, and clinical trials are worth asking about given how uncommon this tumor is.

Follow-up is closer than for many cancers because of the higher chance of this tumor returning, and involves regular examination of the larynx along with imaging. Speech and swallowing therapy and nutrition support are important parts of recovery, particularly after a total laryngectomy, when a speech-language pathologist will work with you on the options for producing speech.

Questions to ask your doctor

Was the diagnosis confirmed by immunohistochemistry, and which markers were positive?
Was a sarcoma ruled out?
Which part of my larynx did the cancer start in?
Did the tumor grow into cartilage or beyond the larynx?
Do my vocal cords still move normally?
Were the surgical margins clear?
Was perineural or lymphovascular invasion found?
How many lymph nodes were removed, and how many contained cancer?
Was extranodal extension present?
What are my pT and pN categories, and what is my overall stage?
Was PD-L1 testing done, and what was the CPS result?
Did my tumor arise in an area that was treated with radiation before, and does that change my options?
What are my treatment options, and is preserving my voice possible?
Is radiation or chemotherapy being considered after surgery?
How often will I be followed, and for how long?