Current role of imaging in the management of children with Wilms tumor according to the new umbrella protocol

Abstract

Wilms tumor is the most common primary renal tumor in childhood. Children with Wilms tumor typically present
with an asymptomatic abdominal mass, usually detected on a routine medical checkup or discovered coincidentally
by parents. The initial differential diagnosis is with extrarenal abdominal masses; once a tumor of renal origin is
established, distinguishing between Wilms tumor and other primary renal neoplasms such as congenital mesoblastic
nephroma, clear cell sarcoma, malignant rhabdoid tumor and renal cell carcinoma may not be easy.
However, in many cases imaging findings in conjunction with the patient’s clinical and epidemiological data, allow
the diagnosis of Wilms tumor. Wilms tumor care offers one of the most striking examples of success of pediatric oncology. Over the last decades the European SIOP studies have been the key to developing standardized diagnostic
procedures, improved risk stratification, and adjusted treatment recommendations for children with Wilms tumor and
this has resulted rate of overall survival is currently greater than 90%. As in previous SIOP trials and studies, the new
protocol for the diagnosis and treatment of childhood renal tumors, the UMBRELLA SIOP–RTSG 2016, mandates
preoperative chemotherapy without preceding mandatory histological assessment.
Therefore, imaging studies are essential to obtain a presumptive diagnosis of WT, to provide disease staging information and to measure the tumor volume after neoadjuvant chemotherapy for the purposes of postoperative treatment
stratification. This review describes role of imaging in the management of children with Wilms tumor, according to
the current recommendations of the UMBRELLA protocol.