Carpal tunnel biopsy
Carpal tunnel biopsy is a test in which a small piece of tissue is removed from the carpal tunnel (part of the wrist).
Biopsy - carpal tunnel
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 diagnose 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.
No abnormal tissues are found.
What Abnormal Results Mean
An abnormal result means that you have amyloidosis.
Risks of this procedure include:
- Damage to the nerve in this area
- Infection (a slight risk any time the skin is broken)
Calandruccio JH. Carpal tunnel syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics. 12th ed. Philadelphia, PA: Elsevier Mosby; 2013:chap 76.
Hawkins PN. Amyloidosis. In: Hochberg MC, Silman AJ, Smolen JS, Weinblatt ME, Weisman MH, eds. Rheumatology. 6th ed. Philadelphia, PA: Elsevier Mosby; 2015:chap 168.
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 Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.