Purpose or Case Report: 1. To discuss anatomy and development of pelvic retroperitoneal structures
2. To discuss etiologies and pathogenesis of pelvic retroperitoneal masses in children
3. To review multimodality imaging features with implications on management
Methods & Materials: Anatomy and development of pelvic retroperitoneal structures; etiologies and pathogenesis of pediatric pelvic retroperitoneal masses; imaging features of various pelvic retroperitoneal masses in children including but not limited to cystic masses such as cystic sacrococcygeal teratoma, tailgut cyst, anterior sacral meningocele, lymphangioma, rectal duplication cyst, hemato/hydrocolpos; vascular lesions such as seen in Klippel-Trénaunay-Weber Syndrome; fat containing masses such as lipoblastoma; malignancies such as sarcoma, ewing’s sarcoma, desmoplastic small round cell tumor, lymphoma, mesenchymal chondrosarcoma; neurogenic tumors such as neuroblastoma; extension from primary bone tumor involving sacrum; discuss implications of imaging on management.
Results:
Conclusions: The pelvic retroperitoneal space is a complex anatomic region that may be affected by a wide variety of masses in children. CT and MR imaging play a central role in the evaluation of primary lesions that occur in this region. Knowledge of the normal anatomy and familiarity with the imaging features and clinical manifestations of these lesions are important for determining the type of mass or narrowing the differential diagnosis, as well as for defining the extent of the mass, an especially important surgical consideration.