Laryngeal Amyloidosis: Understanding Your Pathology Report

Section Editor: Jason Wasserman MD PhD FRCPC
July 27, 2026

Laryngeal amyloidosis is an uncommon condition in which an abnormal protein called amyloid builds up in the tissues of the larynx, the voice box. The deposits make the affected tissue thicker and stiffer, which is why the condition usually affects the voice and, when the buildup is larger, breathing. It is found most often in the vocal cords, the false vocal cords just above them, and the subglottis, the area just below the vocal cords.

Laryngeal amyloidosis is not cancer. It is a benign condition, and it does not turn into cancer.

The question that matters most after this diagnosis is whether the amyloid is confined to the larynx or is part of a wider condition affecting several organs. In most people, it is confined to the larynx, a situation called localized amyloidosis, and the outlook is excellent. Because the two situations are managed very differently, testing to establish which one you have is a routine part of the workup. This is explained further below.

This article explains the findings you are likely to see on a pathology report for laryngeal amyloidosis, what each one means, and why it matters for your care.

What causes laryngeal amyloidosis?

Amyloid is not a single substance. The name describes any protein that has folded into the wrong shape and, as a result, clumps together into deposits that the body cannot clear away. Once these deposits form, they gradually accumulate in the tissue and stiffen it.

In laryngeal amyloidosis, the amyloid is usually made from pieces of antibody proteins called immunoglobulin light chains. These are produced by plasma cells, a type of immune cell. In localized laryngeal amyloidosis, a small population of plasma cells within the larynx itself produces these light chains, and the deposits stay where they are made. This is why the condition remains confined to the voice box in most people.

Why this process begins is not well understood. It is not caused by smoking, alcohol, voice overuse, or infection, and it is not inherited. There is usually nothing a person did or could have done to prevent it.

What are the symptoms of laryngeal amyloidosis?

The symptoms of laryngeal amyloidosis depend on where in the larynx the deposits have formed and how large they are. Because they build up slowly, symptoms often develop gradually over months or years. Common symptoms include:

Hoarseness or a change in the voice, the most common symptom by far
A feeling of something in the throat
A persistent cough or frequent throat clearing
Difficulty breathing, particularly when the deposits are below the vocal cords or are large
Difficulty swallowing
Sore throat

Some people have no symptoms, and the deposits are found during an examination performed for another reason. Because hoarseness has many causes and the buildup is slow, this condition is sometimes present for several years before it is identified.

How is the diagnosis made?

A specialist examining the larynx with a scope may see firm, yellowish or waxy thickened areas, but the appearance alone cannot establish the diagnosis. Confirmation requires a biopsy, usually taken 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.

Under the microscope, a pathologist sees deposits of pink material in the tissue beneath the surface lining. Your report may describe this material as amorphous, meaning it has no organized structure of its own. Because other materials can look similar, the diagnosis is confirmed with additional tests described in the next section.

Congo red and other tests

Confirming that a deposit really is amyloid requires more than its appearance on a routine slide, so additional tests are performed and their results appear on your pathology report:

Congo red stain: positive. Congo red is a special stain that binds specifically to amyloid. When a Congo red slide is viewed under a special microscope using polarized light, amyloid produces a distinctive apple-green color. Your report may describe this as apple-green birefringence. This finding is considered the definitive confirmation that the material is amyloid.
Typing tests: identify which protein formed the amyloid. Because different proteins can form amyloid and the treatment differs, the type is usually determined. This may be done with immunohistochemistry, which uses antibodies to detect specific proteins in tissue, or by a laboratory technique called mass spectrometry, which identifies the protein directly and is more accurate. In the larynx the result is most often the light chain type, described on reports as AL amyloid.

Not every case requires every test. If your report confirms amyloid on Congo red staining and gives a type, that is the information needed to plan the next steps.

Localized and systemic amyloidosis

This is the most important distinction after a diagnosis of laryngeal amyloidosis, and it is worth understanding clearly.

Localized amyloidosis. The amyloid is confined to the larynx and is being produced by plasma cells within the larynx itself. This is the situation for most people with this diagnosis. It does not damage other organs, and the outlook is excellent.
Systemic amyloidosis. Amyloid is being produced elsewhere in the body and deposited in several organs, which may include the heart, kidneys, liver, and nerves as well as the larynx. This is a different and more serious condition requiring treatment directed at the underlying cause.

Because the pathology report alone cannot tell these apart, everyone diagnosed with laryngeal amyloidosis is offered testing to look for evidence of disease elsewhere. This usually includes blood and urine tests, in particular a test measuring free light chains, along with tests of heart and kidney function and sometimes imaging. In a small number of people, systemic amyloidosis is associated with a plasma cell disorder such as a plasma cell neoplasm or multiple myeloma, which these tests would also identify.

The reassuring part is that when this workup is negative, the disease is genuinely localized, and progression from localized laryngeal amyloidosis to systemic disease is uncommon. In published long-term follow-up series, most patients with localized disease never developed systemic amyloidosis.

What happens after the diagnosis?

Treatment for localized laryngeal amyloidosis is directed at symptoms rather than at eliminating the deposits, because the amyloid itself is not dangerous where it sits. Small deposits causing no symptoms may simply be observed. When the deposits affect the voice or breathing, they are removed through a scope passed into the throat, using either fine surgical instruments or a laser depending on where in the larynx they are. The goal is to relieve symptoms while preserving as much normal laryngeal function as possible, so the surgeon usually removes enough to restore the voice or airway rather than attempting to clear every trace.

Two things are worth knowing about what follows. Amyloid deposits commonly build up again over time, and a substantial proportion of people need a repeat procedure, most often within the first few years. This is expected in this condition and does not mean the first procedure failed. Progression tends to slow after that period, though it can occur later.

For this reason, long-term follow-up is recommended, usually with examination of the larynx every six to twelve months at first and continuing for a number of years. Follow-up serves two purposes: identifying regrowth that needs treatment, and repeating the checks for systemic disease if anything changes. Voice therapy with a speech-language pathologist may also be offered if your voice has been affected.

If testing shows systemic amyloidosis, care is led by a specialist team, often including hematology, and treatment is directed at the underlying source of the abnormal protein rather than at the larynx alone.

Questions to ask your doctor

Was the amyloid confirmed with a Congo red stain?
What type of amyloid was found?
Have I been tested for amyloid elsewhere in my body, and what did those tests show?
Is my amyloidosis localized to the larynx, or is it part of a systemic condition?
Do I need to see a hematologist or another specialist?
Where in my larynx are the deposits, and are they affecting my breathing?
Do the deposits need to be removed now, or can they be watched?
How likely is it that the deposits will build up again?
How often will my larynx be examined, and for how long?
Will my voice recover, and would voice therapy help?
What changes should prompt me to call before my next visit?