Carpal tunnel biopsy
Biopsy - carpal tunnel
Carpal tunnel biopsy is a test in which a small piece of tissue is removed from the carpal tunnel (part of the wrist).
How the Test is Performed
The skin of your wrist is cleansed and injected with medicine that numbs the area. Through a small cut, a sample of tissue is removed from the carpal tunnel. This is done by direct removal of tissue or by needle aspiration.
Sometimes this procedure is done at the same time as carpal tunnel release.
How to Prepare for the Test
Follow instructions for not eating or drinking anything for a few hours before the test.
How the Test will Feel
You may feel some stinging or burning when the numbing medicine is injected. You may also feel some pressure or tugging during the procedure. Afterward, the area may be tender or sore for a few days.
Why the Test is Performed
This test is often done to see if you have a condition called amyloidosis. It is not usually done to relieve carpal tunnel syndrome. However, a person with amyloidosis can have carpal tunnel syndrome.
Carpal tunnel syndrome is a condition in which there is excessive pressure on the median nerve. This is the nerve in the wrist that allows feeling and movement to parts of the hand. Carpal tunnel syndrome can lead to numbness, tingling, weakness, or muscle damage in the hand and fingers. Some of these injuries can be permanent, so it is important to have the condition addressed early.
Typing all day on a computer keyboard can be tough on your wrists. If you type for hours at a time, day after day, eventually you may really start to feel some discomfort. The numbness, pain, and tingling you feel in your hands and wrists may be carpal tunnel syndrome, and it can have such a big effect on your life that you may eventually need surgery to treat it. Doing any repetitive motion with your hands, whether it's typing, sewing, driving, or writing, can cause carpal tunnel syndrome. The condition gets its name from an area in your wrist called the carpal tunnel. Running through this tunnel is the median nerve, which sends feeling to your palm and most of your fingers. When you do the same task over and over again, especially flexing and extending the wrist, you put pressure on the median nerve. Over time, it swells up inside the carpal tunnel until it's so tight in there that the nerve gets pinched. The classic symptoms of carpal tunnel syndrome are numbness and tingling in your hand, including the thumb, index, middle, and half of the ring finger. The discomfort is usually worse at night. And anytime you may not be able to grip things as tightly in the affected hand, and you can feel pain that may stretch all the way from the wrist to your elbow. Your doctor can run tests on your hand to confirm that your numbness, weakness, and pain are due to carpal tunnel. You may also have nerve conduction studies, or tests of the muscles. If you're feeling a lot of discomfort from carpal tunnel wearing a wrist splint especially at night could help. In addition, short term oral or injected glucocorticoid medications can help by reducing swelling. Studies have also shown some benefit from physical or occupational therapy techniques, and yoga. About half of the people with carpal tunnel though will eventually need a procedure called carpal tunnel release to lift pressure off the pinched nerve. Surgery is a more permanent solution, but whether it works depends on how severe the nerve damage is, and how long you've had it. You may not be able to completely avoid the repetitive flexing or extending the wrist that gave you carpal tunnel in the first place, especially if it's part of your job. But, you can make some adjustments, for example, by using special devices like a cushioned mouse pad, wrist braces, or a raised keyboard, to relieve the pressure on your wrists. Take occasional breaks whenever you're going to be typing or doing any other repetitive task for long periods of time. And if you are having any numbness, tingling, or pain in your hands or wrists, see your doctor sooner rather than later. Letting carpal tunnel syndrome go untreated could leave you with a permanently damaged nerve.
No abnormal tissues are found.
What Abnormal Results Mean
An abnormal result means that you have amyloidosis. Other medical treatment will be needed for this condition.
Risks of this procedure include:
- Damage to the nerve in this area
- Infection (a slight risk any time the skin is broken)
Hawkins PN. Amyloidosis. In: Hochberg MC, Silman AJ, Smolen JS, Weinblatt ME, Weisman MH, eds. Rheumatology. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 177.
Weller WJ, Calandruccio JH, Jobe MT. Compressive neuropathies of the hand, forearm, and elbow. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 77.
Last reviewed on: 9/20/2022
Reviewed by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.