Pediatric PET-CT

History:  7-year-old female with right nephrectomy for Wilms tumor in January 2007 now presenting with persistent right leg lesion and pain. Rule out metastatic disease.


Right pretibial soft tissue mass is hypermetabolic by positron emission tomography. In conjunction with prior MRI, this almost certainly represents granuloma annulare. No evidence of metastatic disease.

Clinical Utility:  18F-FDG-PET/PET-CT shows promise for identifying metastatic disease, differentiating benign nephrogenic rests and nephroblastomatosis from Wilms' tumor, directing biopsy sites, and contributing to surgical planning (SC Kaste, JS Dome -Practical Pediatric PET Imaging, 2006, pages 256-257).