Amyloidosis is diagnosed with a biopsy. Doctors usually start by taking a sample of fat from your abdomen, although they may need to take more biopsies if they suspect amyloidosis in specific organs. They then examine the tissue sample under a microscope in a lab.

Your doctor may order an abdominal fat pad biopsy if you have early signs of amyloidosis, such as unexplained weight loss, shortness of breath, paresthesias (tingling, numbness, or other altered sensations), or ruptured tendons.

This article explains what you need to know about an abdominal fat pad biopsy, including what to expect and how doctors use the results.

🗳️ Did your doctor need additional testing after your abdominal fat pad biopsy to diagnose your amyloidosis?

No, that was the only test needed for diagnosis.

Yes, they repeated the abdominal fat pad biopsy.

Yes, they biopsied another part of my body.

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What Is an Abdominal Fat Pad Biopsy?

The abdominal fat pad lies just beneath the skin on the front of your abdomen, over your abdominal muscles. Because this layer is easy to reach, an abdominal fat pad biopsy is a minimally invasive procedure compared to many other types of biopsies.

During an abdominal fat pad biopsy, a healthcare professional removes a small sample of abdominal fat using a syringe or another method. The sample usually contains five to 10 tiny pieces of abdominal fat. In many cases, the fat stays inside the syringe, which is capped and sent to the lab.

In the lab, a technician removes the fat samples and stains them with a dye called Congo red. The dye helps doctors identify amyloid proteins. If amyloid is present, the deposits appear bright green when viewed under polarized light after Congo red staining.

What To Expect When You Have an Abdominal Fat Pad Biopsy

If your doctor has ordered an abdominal fat pad tissue biopsy, knowing what to expect may help you feel more prepared for the procedure. The exact steps may vary, but here is a general overview.

Needle aspiration is the most common way to perform abdominal fat pad biopsy, and that’s the procedure outlined here.

Some doctors may use an excisional abdominal fat pad biopsy instead. During this procedure, they remove a small piece of the fat pad through a small incision instead of using a syringe. Although this method is slightly more invasive than needle aspiration, it may be more likely to provide enough tissue for an accurate diagnosis.

Before an Abdominal Fat Pad Biopsy

You don’t usually have to do anything special to prepare for an abdominal fat pad biopsy. If your doctor does give you specific instructions, follow them closely.

After you check in, you’ll be asked to lie back in a reclined position. A doctor or technician will clean the area of your abdomen where they plan to take the sample. They’ll then inject a local anesthetic to numb the area.

During an Abdominal Fat Pad Biopsy

Once the area is numb, your doctor will insert a needle through the skin of your abdomen. It will go through your skin and into the layer of fat beneath it. The needle doesn’t go very deep.

Your doctor will move the needle under your skin while using the syringe to collect tiny pieces of fat. They may need to insert the needle two to four times to get enough tissue.

You may feel pressure or discomfort during the biopsy, but the local anesthetic should prevent pain. If you do feel pain at any point, let a member of your care team know right away.

After an Abdominal Fat Pad Biopsy

Your doctor may apply antibiotic ointment and a bandage where the needle was inserted. Follow their instructions for caring for these small wounds.

You should also keep an eye out for bleeding, bruising, or signs of an infection in and around the needle insertion sites. Signs of an infection include:

• Pain around the wound that gets worse instead of better
• Increasing discoloration around the wound
• Swelling that gets worse
• Skin around the wound that feels warm or hot to the touch
• Fever or body aches

If you have any of these symptoms, contact your healthcare professional. You may need additional evaluation or wound care.

How Are Results From an Abdominal Fat Pad Biopsy Used?

An abdominal fat pad biopsy can give doctors important information, but it’s not the only tool used to diagnose amyloidosis. In some cases, it may not detect the disease.

The accuracy of an abdominal fat pad biopsy depends in part on the type of amyloidosis. If you have amyloid light-chain amyloidosis, the biopsy is more likely to detect amyloid deposits. If you have ATTR amyloidosis, however, this test is less sensitive and may not detect the disease.

It’s possible to have a negative abdominal fat pad biopsy result and still have amyloidosis. If your doctor still suspects amyloidosis after your biopsy, they may recommend additional tests to help confirm or rule out the diagnosis.

The amount of tissue collected also affects how accurate the test is. A larger sample is more likely than a smaller one to contain amyloid deposits. If the sample is too small, your doctor may want to repeat the test to collect more tissue.

Abdominal Fat Pad Biopsy and Cardiac Amyloidosis

Cardiac amyloidosis develops when amyloid proteins build up in the heart muscle, which can make it harder for the heart to pump blood effectively.

An abdominal fat pad biopsy may help diagnose cardiac amyloidosis. If the biopsy detects amyloid and identifies the type of amyloid protein involved, you may be able to avoid a heart biopsy, which is a more invasive procedure.

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On MyAmyloidosisTeam, people share their experiences with amyloidosis, get advice, and find support from others who understand.

Did you have an abdominal fat pad biopsy as part of your amyloidosis diagnosis? What was the procedure like for you? Let others know in the comments below.