Flexor tendon tenosynovitis with rice body formation in rheumatoid arthritis

Abstract

A 69-year-old man, known with rheumatoid arthritis was admitted to the orthopaedic surgery department with swelling of the right wrist. Physical examination confirmed the swelling located at the palmar side of the wrist. There was a slightly decreased range of motion of the wrist. The patient was not aware of a recent trauma. The patient is known with an erosive destruction of the wrist in the context of rheumatoid arthritis. The initial X-ray of the wrist confirmed an erosive destruction of the carpus with SLAC wrist deformity (Fig. A), associated with a remarkable volar soft tissue mass obliterating the pronator fat pad on the lateral view (not shown). Ultrasound of the wrist illustrated a hypo-echogenic polylobular mass in between the flexor tendons of the wrist (Fig. B). Further assessment with MRI confirmed synovitis of all flexor tendons with multiple intrasynovial nodules, T1 iso-intense (Fig. C) and T2 iso- to slightly-hyperintense (Fig. D) compared to muscular tissue. These intrasynovial nodules are avascular showing no enhancement on T1+ Gd (Fig. E), surrounded by a hyperintense synovial wall post contrast administration (Fig. E). Imaging findings are compatible with chronic synovitis associated with rice body formation.