Giant cell tumor of the tendon sheath arising from a membrane surrounding the posterior arch of C1: a case report

Background ContextGiant cell tumor of the tendon sheath (GCTTS) is a common, benign lesion of the synovial membrane that occurs more often in large joints than in digits. Giant cell tumor of the tendon sheath rarely arises in close proximity to the axial skeleton.PurposeThe purpose of the study was to report a rare case of GCTTS arising from the membrane surrounding the posterior arch of the atlas (C1).Study Design/SettingThis is a case report.MethodsThe methods involve clinical findings and review of current literature.ResultsIn this report, we describe a rare case of GCTTS arising from the membrane surrounding the posterior arch of C1, with no apparent continuity with the facet joint. Here we show the radiographic features, with particular emphasis on positron emission tomography-computerized tomography scans, which have not been previously reported.ConclusionsWe experienced an extremely rare case of GCTTS arising from the membrane surrounding the posterior arch of the C1 vertebra. In spite of the rarity of this disease, GCTTS should be considered in the differential diagnosis of the axial skeletal lesion. Awareness of GCTTS is important because its radiographic features may simulate other neoplastic lesions in the spine.