Tenosynovitis with acute onset: unexpected giant cell tumour of the tendon sheath.

The “case study in diagnostic imaging”, reported by Peh et al illustrates nicely a giant cell tumour of the tendon sheath as a slowly progressing, mildly tender mass of the wrist. Here we report another case of giant cell tumour of the tendon sheath, which had an unusual disease onset. A 33 year old man presented with acute swelling and severe pain of the palmar side of the right hand. He had symptoms of carpal tunnel syndrome, and upon clinical examination swelling of the flexor tendon sheaths of the wrist as well as the fourth and fifth fingers was seen. There was no history of trauma or exposure to tuberculosis. His erythrocyte sedimentation rate and C reactive protein were within the normal range; rheumatoid factor was absent. Mantoux testing and a chest x ray examination were negative. A radiograph of the right hand was normal. Because of deteriorating pain and swelling, a surgical exploration with tenosynovectomy was performed. Macroscopically this showed an exuberant brownish synovial proliferation with numerous villonodular projections, which was not encapsulated. There was no evidence for recent haemorrhage. Histological examination showed proliferation of the synovial lining, subintimal infiltration with mononuclear polyhedral cells— often with a histiocytic aspect, scattered multinucleated giant cells (fig 1A), and haemosiderin laden and lipid laden macrophages (fig 1B). Although the infiltrate was markedly dense, regional variations in cellularity were seen. Compact areas alternated with more non-cohesive zones with cleft-like spaces appearing as artificial tears. This histological pattern is characteristic for a diffuse giant cell tumour of the tendon sheath, which is histologically very similar to pigmented villonodular synovitis. Differential diagnosis of tenosynovitis of the hand with occurrence of multinucleated giant cells is a feature of rheumatic diseases such as rheumatoid arthritis, tubercular and non-tubercular mycobacterial infections, and foreign body granulomas. In this patient neither his history or additional examinations suggested these diseases, although acute onset and severe pain are not commonly reported in giant cell tumour of the tendon sheath.