Maxillofacial and Axial/Appendicular Giant Cell Lesions: Unique Tumors or Variants of the Same Disease?-A Comparison of Phenotypic, Clinical, and Radiographic Characteristics

Purpose: The relationship between giant cell lesions (GCLs) of the maxillofacial (MF) skeleton and those of the axial/appendicular (AA) skeleton has been long debated. The present study compared the clinical and radiographic characteristics of subjects with MF and AA GCLs. Materials and Methods: This was a retrospective cohort study of patients treated for GCLs at Massachusetts General Hospital from 1993 to 2008. The predictor variables included tumor location (MF or AA) and clinical behavior (aggressive or nonaggressive). The outcome variables included demographic, clinical, and radiographic parameters, treatments, and outcomes. Descriptive and bivariate statistics were computed, and P <= .05 was considered significant. Results: The sample included 93 subjects: 45 with MF (38 with aggressive and 7 with nonaggressive) and 48 with AA (30 with aggressive and 18 with nonaggressive). Comparing the patients with MF and AA GCLs, those with MF lesions presented younger (P < .001), and the lesions were more commonly asymptomatic (P < .001), smaller (P <.001), and managed differently (P < .001) than AA lesions. When stratified by clinical behavior, aggressive tumors were diagnosed earlier than nonaggressive tumors (P <.001). Controlling for location and clinical behavior, patients with MF aggressive lesions were younger (P <.001) than those with AA aggressive lesions. MF nonaggressive lesions were more commonly asymptomatic (P = .04), smaller (P = .05), and less commonly locally destructive (P = .05) than AA nonaggressive lesions. Conclusions: These results suggest that MF and AA GCLs represent a similar, if not the same, disease. Comparing the aggressive and nonaggressive subgroups, more similarities were found than when evaluating without stratification by clinical behavior. The remaining differences could be explained by