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

Abstract

BackgroundNephroblastomatosis 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 presentationWe 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.Conclusion3.5 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.

Nephroblastomatosis and wilms tumor: dangerous liaisons

“…Most retrieved papers consisted either of multicentric retrospective reviews reporting on long periods of time (2,6) or case reports (1,(7)(8)(9)(10)(11)(12)(13)(14)(15). The most exhaustive paper available, a multicentric review from Perlman et al, reports on 52 cases/30 years (less than 2/year), while covering more than 90% of the cases registered in the USA (2).…”

“…4 -MRI (gold standard): nodules hypointense to the cortex and isointense to the medulla in T1 and hyperintense in T2 weighted images, hypocaptating as compared to normal kidney tissue (2, 8) (Figure -2B). MRI can help to differentiate hyperplastic nodules and WT, as benign nodules are characteristically uniform and ovoid/ lenticular, while WT tends to be spherical, exophytic, and heterogeneous, due to interposed areas of hemorrhage and necrosis (10). Those differential characteristics may not present, especially in small tumors.…”

“…HDNBM normally responds to chemotherapy with quick regression of the proliferative nodules, but the length of the treatment is controversial and the problem may recur (2,7). Regression may be demonstrated histologically (10), with differentiation of embryonal tissue. Sclerotic rests may also be demonstrated in MRI (2).…”