Multinodular hyperplastic pannephric nephroblastomatosis with tubular differentiation: a new morphologic variant

Bilateral renal dysplasia, nephroblastomatosis, and bronchial stenosis. A new syndrome?

Bilateral nephroblastomatosis (NB) is an uncommon renal anomaly characterized by multiple confluent nephrogenic rests scattered through both kidneys, with only a limited number of cases reported in the medical literature. Some of these children may have associated either Perlman or Beckwith-Wiedemann syndrome and others do not demonstrate syndromic features. We report a full-term boy with anteverted nose, bilateral bronchial stenosis due to lack of cartilage, bilateral obstructive renal dysplasia and NB with glomeruloid features. The infant had visceromegaly, but neither gigantism nor hemihypertrophy. Immunohistochemistry for PAX2 (Paired box gene-2) and WT-1 (Wilms Tumor 1) were strongly positive in the areas of NB. GLEPP-1 (Glomerular Epithelial Protein) did not stain the areas of NB with a glomeruloid appearance, but was positive in the renal glomeruli as expected. We found neither associated bronchial stenosis nor the histology of NB resembling giant glomeruli in any of the reported cases of NB.

Perilobar nephroblastomatosis: natural history and management

Nephroblastomatosis (NB) has been considered as a precursor of Wilms tumor (WT). The natural history of NB seems to present significant variation as some lesions may regress spontaneously, while others may grow and expand or relapse and develop into WT later in childhood. Although, most investigators suggest adjutant chemotherapy, the effect and duration of treatment are not well established. Children with diffuse perilobar NB, Beckwith-Wiedemann syndrome, and hemihypertrophy seem to particularly benefit from treatment. We discuss our experience on two cases of NB and we review the literature for the management of this rare condition.