Pediatric Renal Masses: Wilms Tumor and Beyond

Abstract

A variety of pediatric renal masses may be differentiated from Wilms tumor on the basis of their clinical and imaging features. Wilms tumor is distinguished by vascular invasion and displacement of structures and is bilateral in approximately 10% of cases. Nephroblastomatosis occurs most often in neonates and is characterized by multiple bilateral subcapsular masses, often associated with Wilms tumors. Renal cell carcinoma is unusual in children except in association with von Hippel-Lindau syndrome and typically occurs in the 2nd decade. Mesoblastic nephroma is the primary consideration in a neonate with a solid renal mass. Multilocular cystic renal tumor is suggested by a large mass with multiple cysts and little solid tissue. Clear cell sarcoma is distinguished by frequent skeletal metastases, and rhabdoid tumor is distinguished by its association with brain neoplasms. Angiomyolipoma frequently contains fat and is associated with tuberous sclerosis. Renal medullary carcinoma occurs in patients with sickle cell trait or hemoglobin SC disease and manifests as an infiltrative mass with metastases. Ossifying renal tumor of infancy is differentiated from mesoblastic nephroma by the presence of ossified elements. Metanephric adenoma lacks specific features but is always well defined. Renal lymphoma is characterized by multiple homogeneous masses, often with associated adenopathy.

SIOP PODC: Clinical guidelines for the management of children with Wilms tumour in a low income setting

“…Ultrasonography of the abdomen is extremely useful to confirm the diagnosis [12][13][14] (Table III). It is also a non-invasive, useful diagnostic tool for many general paediatric patients in setting 1.…”

Congenital Mesoblastic Nephroma Presenting with Neonatal Hypertension

“…It does not typically encase or elevate the aorta as does a neuroblastoma. 9 Heterogeneous echogenicity represents hemorrhage, fat, necrosis or calcification. CT demonstrates the heterogeneous mass and nodal metastases, as well as areas of calcification and occasionally fat.…”

“…At MRI, Wilms' tumor demonstrates low-signal intensity on T1-weighted images and high-signal intensity on T2-weighted images. 1,9 It may be impossible to distinguish congenital mesoblastic nephroma from Wilms' tumor by any radiographic study. 2 Earlier presentation and usual unilateral involvement may suggest mesoblastic nephroma, but histology is the only means of confirming the diagnosis.…”

Bilateral Panlobar Nephroblasyomatosis and Bladder Neck Polyp in a Newborn

“…Nephroblastomatosis predisposes to the development of Wilms tumor. 2 In a previous study, the prevalence of renal rests (0.87 %) and the incidence of Wilms' tumor was reported approximately 1 in 10000 infants. Panlobar nephroblastomatosis is an very rare entity 1,6 Here, we report a case with bilateral nephromegaly detected prenatally, who had blaldder neck polyp and diffuse NB.…”