Trigger Wrist Caused by a Rheumatoid Nodule on the Flexor Pollicis Longus Tendon.

Background: Trigger wrist is a rare condition. Previously reported cases have involved nodules or ganglion cysts affecting flexor digitorum profundus tendons; however, we found no reported cases of trigger wrist caused by a rheumatoid nodule on the flexor pollicis longus tendon. Case Report: A 57-year-old female presented with the complaint of chronic triggering of the right thumb and numbness in her fingers consistent with carpal tunnel syndrome. Corticosteroid injection did not provide symptom relief, so the patient was scheduled for surgery. A 3 × 1.5-cm lesion was removed from the flexor pollicis longus tendon distal to the carpal tunnel. Histopathologic examination demonstrated that the lesion was a rheumatoid nodule. Conclusion: Patients with rheumatoid arthritis who present with trigger finger symptoms of the thumb with concomitant carpal tunnel symptoms require careful evaluation to rule out trigger wrist before the condition progresses to Mannerfelt lesion.