Wilms tumor: diagnosis and updates

Although Wilms tumor is the most common malignant renal tumor of childhood, it is an overall rare malignancy with a variety of histological appearances. As clinical trials have sought to further identify groups of patients who can benefit from escalation or de-escalation of therapy, an increasing number of histopathological and molecular factors have become important factors in patient risk stratification. This manuscript reviews the clinical presentation and typical histologic findings in Wilms tumor. The differential diagnostic considerations are explored, with practical recommendations for immunohistochemical and molecular workup to aid in accurate diagnosis. Finally, important known and emerging elements relevant to risk stratification are outlined, including pre- and post-therapy histological classification, staging, and important molecular findings.