MR Findings of Extraabdominal Desmold Tumors: Correlation with H istopathologic Findings

PURPOSE: To understand the MR findings of extraabdominal desmold tumors by correlation with histopathologic findings. MATERIALS AND METHODS: MR images of histologically proved 12 patients with extraabdominal desmold tumor were retrospectively reviewed. Three types of MR features were defined; type I had signal changes on T1 and T2 weighted images and relatively homogeneous nature, type II had homogeneously low signal intensities on T1 and T2 weighted images and type III was a mixed form of type I and type II. Signal intensity, enhancement pattern and margin of the lesions were analyzed on MR images. Pathologic features were analyzed by three aspects, which were cellularity, amount of collagen and vascularity, and were correlated with MR images. RESULTS: The signal intensities of type I desmolds were intermediate on T1 weighted image and higher on T2 weighted image with localized margin and gadolinium enhancement. Pathologically this type showed predominant cellularity and vascularity. The signal intensities of type II desmold were homogenous low signal intensities on both T1 and T2 weighted images without enhancement. Pathologically this type showed predominant collagen components and hypovascularity. Type III desmolds were mixed form of type I and type II on MR images as well as on pathologic features. Type I and type II desmold tumors had localized margins, however type III had both localized and infiltrative margins. CONCLUSION: The MR findings of extraabdominal desmold tumors would reflect the pathologic background of the tumor.