DIFFERENT BIOLOGIC FEATURES OF DESMOID TUMORS IN ADULT AND JUVENILE PATIENTS - MR DEMONSTRATION

Objective: To demonstrate different biologic features of desmoid tumor s on MRI between juvenile and adult patients. Materials and Methods: W e 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 statis tical analysis. Results: Recurrences in the juvenile patients were mor e multiple (50 vs 12%) and appeared significantly earlier than in the adult patients. Adult patients demonstrate a much greater recurrence-f ree rate (p = 0.0001). Infiltrative pattern was significantly predomin ant in the juvenile patients (63%) whereas the nodular pattern was mor e frequent in the adult patients (81%). Low-signal intensity zones on T1- and T2-weighted imaging as well as the type of contrast enhancemen t 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 dem onstrates different biologic features between juvenile and adult patie nts with histologically same desmoid tumors. These differences may be useful consideration of MRI follow-up studies.