Wegener's granulomatosis and giant cell tumor of tendon sheaths: casual or causal combination? First case report.

Giant cell tumor of tendon sheath (GCTTS) and Wegener's granulomatosis (WG) are rare conditions both characterized by polyclonal cellular proliferation and multinucleated giant cells formation. Here, we report the case of a 27-year-old Caucasian woman affected by WG who experienced the metachrone appearance of two different GCTTSs at the right hand within a time of 3 years. To our knowledge, the combination of GCTT with WG is exceptional and this could probably be the first case reported. The subsequent appearance of two rare diseases both characterized by giant cell formation apparently points to similarities in their pathogenesis. However, at present no pathogenic relationship between GCTTS and WG is demonstrable and their simultaneous occurrence has to be considered coincidental. Actually, an emerging opinion is to consider GCTTS as a mixed lesion in which both tumoral and non-tumoral inflammatory cells play a central pathogenic action. On this view, the proposed case could support the evidence about the crucial role of a chronic inflammatory injury in enhancing GCTTS appearance.