Conventional MRI and dynamic contrast-enhanced MRI in differentiating histopathological subtypes of giant cell tumor of bone

Background and Aim: Giant cell tumor of bone (GCTB) is a locally aggressive neoplasm with heterogeneous biological behavior, including conventional and malignant subtypes.Accurate preoperative differentiation remains clinically important yet challenging.Although histopathology remains the gold standard for diagnosis, it is invasive and limited in assessing tumor heterogeneity.Conventional MRI is widely used but has limited ability to distinguish histopathological subtypes due to overlapping imaging features. Dynamic contrast-enhanced MRI (DCE-MRI), which reflects tumor perfusion and vascular permeability, may provide additional discriminatory information; however, comparative evidence with conventional MRI remains limited.This study aims to compare conventional MRI and DCE-MRI in differentiating histopathological subtypes of GCTB. Methods: This retrospective cross-sectional study included 31 patients with histopathologically confirmed GCTB who underwent conventional MRI and DCE-MRI between January 2020 and February 2026.Conventional MRI parameters included tumor volume, solid component volume ratio, and septal thickness. DCE-MRI analysis comprised qualitative (time–intensity curve [TIC] patterns), semi-quantitative (maximum slope and IAUGC), and quantitative parameters (Ktrans, Kep, and Ve). Imaging findings were compared between conventional and malignant subtypes. Results: Most cases were conventional GCTB (87.1%), with a slight male predominance (54.8%) and the majority aged 20–40 years (58.1%). Lesions were most frequently located in the lower extremities (61.3%), particularly the tibia and femur. Conventional MRI parameters showed no significant differences between histopathological subtypes (p>0.05). Among DCE-MRI parameters, TIC patterns were not significantly different (p=0.340), although all malignant cases demonstrated a type IV pattern. In contrast, quantitative and semi-quantitative DCE-MRI parameters showed significant differences, with higher median values of Ktrans (p=0.009), Kep (p=0.002), IAUGC (p=0.012), and maximum slope (p=0.023) in malignant GCTB, while Ve showed no significant difference (p=0.396). Conclusions: Conventional MRI has limited ability to differentiate histopathological subtypes of GCTB.In contrast, DCE-MRI parameters provide significant discriminatory information between conventional and malignant subtypes, supporting its role as a non-invasive tool for tumor characterization.