Is Wilms Tumor Congenital?

Is Wilms Tumor Congenital?

The exact cause or pathogenesis of Wilms’ tumor (WT) is not known clearly, but it can be due to genetic and non-genetic causes. Wilms’ tumor develops from embryonic kidney cells which have not developed simultaneously with the other embryonic cells. These cells tend to have some connection with the course of the disease.

Studies have not found any association between Wilms’ tumor and environmental factors exposed during pregnancy or after delivery. Most cases of Wilms’ tumor are sporadic. 1-2% of tumors are familial and there is a family history of a close relative diagnosed with Wilms’ tumor.

Is Wilms Tumor Congenital?

12-15% of cases or 1 in 10 with Wilms’ tumor are associated with congenital birth defects and most of these birth defects are associated with a syndrome.

Wilms’ tumor is linked up with some birth defects which do not include into a syndrome such as:

Aniridia – complete or partial loss of the iris of the eye

Hemihypertrophy – oversized leg or arm either on one side of the body

Cryptorchidism – failure of the testicles to descend down to the scrotum

Hypospadias – the urethral opening is on the underside of the penis. (1)

The common syndromes Wilms’ tumor is associated are:

This association between Wilms’ tumor and birth defects and congenital syndromes suggests it can be a congenital disease. The abnormal cells in the kidneys might be present from birth and these cells grow and multiply which leads to the manifestation of symptoms and diagnosis of Wilms’ tumor.

There have been few case reports of Wilms’ tumor diagnosed during the pregnancy period. One case report was on a 20-year-old woman who presented at 28 weeks with a fetal intraabdominal tumor. There was fetal hydrops fetalis, well-capsulated mass in the left upper abdomen and the left kidney was not able to identify in the scan. Then a percutaneous ultrasound-guided biopsy was performed, after the procedure, the condition of the fetus was not stable therefore, an emergency cesarean section was performed but unfortunately, the fetus was dead at birth. The postmortem examination revealed a left kidney replaced by an encapsulated tumor, bicornuate uterus, and biventricular hypertrophy was present in the heart. There were not any dysmorphic features and the other organs were normal. The histological examination confirmed a congenital Wilms’ tumor. (2) (3)

Congenital Wilms’ tumor is associated with polyhydramnios (increase amniotic fluid levels) and hydrops fetalis. It is rather difficult to identify the tumor through an ultrasound scan as it continues with the kidney. Usually, congenital Wilms’ tumor is capsulated but it is not well-defined and it blends in with the remaining normal kidney.

This shows that Wilms’ tumor can be congenital but there are not many case reports or studies involved in fetuses with congenital Wilms’ tumor. It might be due to the lack of diagnosis during the pregnancy period because the tumor is small and it will not be detected by an ultrasound scan. The fetuses that develop large Wilms’ tumors will get hydrops fetalis and polyhydramnios therefore, these fetuses will be detected but most of these fetuses will not live after birth. (3) (4)


The exact cause of Wilms tumor is not known clearly but it is associated with some of the birth defects such as aniridia, hemihypertrophy, cryptorchidism, hypospadias; and with congenital syndromes such as WAGR syndrome, Denys-Drash syndrome, Frasier syndrome, and Beckwith-Wiedemann syndrome. Therefore, Wilms’ tumor can be a congenital condition. Although Wilms’ tumor commonly occurs in children age 3-7 years it might be present from birth but the symptoms manifest later in life. This is supported further by the case reports published on pregnant women with fetuses diagnosed with congenital Wilms’ tumor.


Also Read: