Objective: To demonstrate different biologic features of desmoid tumors on MRI between juvenile and adult patients.
Materials and methods: We have retrospectively analyzed clinical records and 121 MRI findings in 40 patients (8 juveniles and 32 adults) with proven desmoid tumors. The Fisher exact test and Kaplan-Meier curve were utilized for statistical analysis.
Results: Recurrences in the juvenile patients were more multiple (50 vs 12%) and appeared significantly earlier than in the adult patients. Adult patients demonstrate a much greater recurrence-free rate (p = 0.0001). Infiltrative pattern was significantly predominant in the juvenile patients (63%) whereas the nodular pattern was more frequent in the adult patients (81%). Low-signal intensity zones on T1- and T2-weighted imaging as well as the type of contrast enhancement did not show any significant relationship with biological behavior. Four cases with no significant contrast enhancement showed low signal intensities on T2-weighted imaging.
Conclusion: Magnetic resonance demonstrates different biologic features between juvenile and adult patients with histologically same desmoid tumors. These differences may be useful in consideration of MRI follow-up studies.