Diffuse Hyperplastic Perilobar Nephroblastomatosis

Abstract

Nephroblastomatosis is a rare preneoplastic lesion defined as the presence of diffuse or multifocal nephrogenic rests. They are divided into 4 categories: perilobar, intralobar, combined, and universal. The aim of this report is to describe a case of diffuse hyperplastic perilobar nephroblastomatosis. A 1-year-old boy presented with an abdominal mass on the left side. Computed tomography scan showed a homogeneous, isointense enlarged left kidney. A fine needle aspiration cytology was reported as Wilms tumor. After chemotherapy, the left kidney was excised. Nephrectomy specimen presented a thick cortical rim of hyperplastic nephrogenic tissue, well delineated from preserved renal parenchyma without pseudocapsule. Nephroblastomatosis is a rare condition affecting renal parenchyma. Diagnosis is based on imaging studies, such as ultrasound, computed tomography scan, and magnetic resonance imaging. Fine needle aspiration cytology is of limited value. Therapeutic management is controversial. Chemotherapy is used preoperatively, and surgical excision may be an alternative for refractory cases.

Nephroblastomatosis and wilms tumor: dangerous liaisons

“…The median weight of affected kidneys may attain 10 times normal (2). Unilateral cases are exceptional (9). Severe asymmetry suggests malignant degeneration attaining dominant nodules, which are suspicious of WT, as in our first patient.…”

“…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).…”

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

“…Nephroblastomatosis is a premalignant condition typified by multiple residual embryonal cells known as nephrogenic rests [ 2 ]. Nephrogenic rests are clusters of embryonic metanephric cells found incidentally in 1% of infants that can exist as single or multiple, focal or diffuse lesions within the renal parenchyma.…”

Ectopic nephrogenic rest in the inguinal canal in a 6-month-old girl and a review of published studies

“…Extrarenal WTs are usually round-shaped, form a fibrous pseudocapsule around the lesion, and show atypical mitoses or anaplasia. 7 , 8 Specifically, a nephrogenic rest resembles a favorable histology WT; no clear pathologic separation of the two is observed. In the present case, the nodular pattern and the gradual transition of resting embryonal clusters to cellular blastemal nodules without a dissecting limiting fibrous capsule leaned more toward ENR.…”