[ATTR Amyloidosis for Hand Surgeons: A Hidden, Treatable Systemic Disease]

There is strong evidence that carpal tunnel syndrome (CTS) - particularly when bilateral, recurrent or occurring in older adults - is frequently associated with a life-threatening systemic disease, transthyretin (ATTR) amyloidosis. It should, therefore, be recognised as a potential early manifestation of ATTR amyloidosis and prompt further investigations. In this article, we highlight the significance of CTS in the context of amyloidosis and emphasise the key diagnostic steps that should be taken when amyloid is detected in the transverse carpal ligament. These include histopathological subtyping, serum testing for light chains to rule out or enable rapid treatment of AL amyloidosis, and - especially in the presence of cardiomyopathic symptoms - diagnostic evaluation for cardiac amyloidosis as well as genetic testing in cases where ATTR amyloid is identified. In summary, carpal tunnel syndrome is an important early indication of a fatal yet treatable systemic disease that should not be overlooked. Hand surgeons should, therefore, pay particular attention to patients with CTS and, whenever possible, incorporate a histopathological examination of the excised tissue into routine practice.