Case report: Diffuse hyperplastic perilobar nephroblastomatosis complicated by a unilateral Wilms tumour: diagnosis, treatment and follow-up

BACKGROUND: Nephroblastomatosis is an uncommon pathologic process characterized by the presence of persistent embryonic nephrogenic rests. Progression to Wilms tumour occurs in an estimated 35% of patients. Cure rates are based on histologic findings and disease stage and have improved from 10% in the 1920s to over 90% today. CASE PRESENTATION: We report a case of a 9-month-old female presenting with a 2-month history of abdominal distension. Ultrasonographic and computed tomographic assessments demonstrated features consistent with bilateral, diffuse, hyperplastic perilobar nephroblastomatosis (DHPLNB) for which she underwent chemotherapy. Magnetic resonance imaging 6 weeks following commencement of chemotherapy revealed a mass concerning for unilateral Wilms tumor for which she underwent partial nephrectomy. Pathology confirmed DHPLNB with a unilateral Wilms tumor. CONCLUSION: 3.5 year radiographic follow up demonstrates complete recovery. To our knowledge, there are no similar cases with imaging depiction recently published. With potential for malignant transformation into Wilms tumour and low survival rate for late diagnosed Wilms tumors, it is important to recognize nephroblastomatosis early, both clinically and radiographically to improve overall patient prognosis.