Contribution of Magnetic Resonance Imaging to Prenatal Differential Diagnosis of Renal Tumors: Report of Two Cases and Review of the Literature

Abstract

Enlargement of a kidney on prenatal imaging is usually due to hydronephrosis or cystic renal disease, and much less often results from solid tumors such as mesoblastic nephroma, Wilms’ tumor, nephroblastomatosis, renal sarcoma, and angiomyolipoma. All can be diagnosed by ultrasound. Magnetic resonance imaging is useful not only in confirming the presence of a renal mass, but also in the evaluation of the contralateral kidney for subtle abnormalities. We present one case each of Wilms’ tumor and mesoblastic nephroma, both detected on antenatal ultrasound and further studied with fetal magnetic resonance imaging.

Prenatal Diagnosis of Congenital Mesoblastic Nephroma

“…The differential diagnosis of a solid renal mass includes Wilms’ tumor, adrenal masses, cross-fused ectopia, autosomal recessive polycystic kidney disease, diffuse nephroblastomatosis, Beckwith-Wiedemann syndrome and compensatory hypertrophy in case of absence of the contralateral kidney. Linam et al [4] discussed the contribution of MRI to prenatal differential diagnosis concluding that all renal masses can be diagnosed by ultrasound completed with MRI in case of doubt and also in the evaluation of the contralateral kidney for subtle abnormalities. In our case the use of MRI permitted the correct diagnosis and improved the management and treatment after birth.…”

Is antenatal detection of Wilms′ tumor a bad prognostic marker?

“…[1] Antenatal detection of Wilms’ tumor is very rare and only nine cases have been reported till now. [1–7]…”

Bilateral Wilms tumor with neonatal onset and the importance of prenatal diagnosis

“…A prenatal diagnosis of WT is very important because the families can take advantage of prenatal counseling to understand the risks of continuing the pregnancy and to evaluate the need for abortion, while health care providers can prepare to face a difficult delivery. In five of the previously reported cases, the surgical operation was performed as soon as possible to avoid rupture of the mass and/or to increase the chance of survival of the infants (5,6,11,12,14). In one case, intrauterine treatment was performed at 28+2 weeks to decompress the mass of the tumor, however, the surgery failed and the infant died 20 minutes after its preterm birth (12).…”

“…De Bernardo G et al The National Wilms Tumor Study Group registered 6832 patients with WT from 1969 to January 1993, out of whom only 11 patients (0.16%) were newborns (3). Bilateral WT is most frequently diagnosed and recorded in patients aged between 30-33 months, with only 2 cases presenting during the prenatal period (2,4,5).…”