Desmoplastic small round cell tumor: imaging findings associated with clinicopathologic features.

Purpose: To describe imaging findings of desmoplastic small round cell tumor (DSCRT) and to clarify the relation between radiologic appearances and clinicopathologic features.
Materials and Methods: CT scans and MRI examinations of four male patients with histologically confirmed DSCRT (mean age = 20 years) were retrospectively analyzed.
Results: The common imaging finding was multiple peritoneal masses with regular contour situated within mesentery. Tumors showed central low attenuation in 75% of patients on nonenhanced CT. All tumors showed inhomogeneous enhancement on CT. Small foci of punctate calcification were identified in a part of the tumor in all patients. Bone metastases were identified on enhanced CT in two patients 2 and 8 months after diagnosis, respectively. Pleural dissemination was identified in all patients, and one patient had double-sided dissemination. T2-weighted MRI showed inhomogeneous high signal intensity, and small cysts were identified in two patients. Fluid-fluid levels were identified in six tumors on T2-weighted images, which suggested the presence of hemorrhage. Tumors had inhomogeneous signal intensity low or isointense relative to skeletal muscle on T1-weighted images. Two lesions exhibited inhomogeneous enhancement with central low intensity consistent with necrosis.
Conclusion: Imaging studies can depict disseminated characteristics and disease extent during the clinical course of DSRCT.