A rare coincidence of intrarenal Wilms tumor with spina bifida: a case report and review of the literature.

INTRODUCTION: Children with congenital anomalies are at increased risk of childhood malignancies. Among these, children with nervous system and urinary system anomalies have the highest incidence rate of cancer. This is a report of an intrarenal Wilm's tumor in a patient with spina bifida. CASE PRESENTATION: A 4-month-old male baby with a repaired lumbosacral myelomeningocele presented with right flank swelling. At presentation, a firm, slightly mobile, and nontender right flank mass was noted. Abdominopelvic ultrasound performed at a neonatal age revealed an 8 mm right renal cyst at the lower pole without septa or mural nodules. Magnetic resonance imaging performed at his recent presentation was suggestive of Wilm's tumor. The histopathology revealed cystic, partially differentiated nephroblastoma with negative lymph nodes. It's a SIOP stage 1 low-risk tumor that doesn't deserve adjuvant chemoradiotherapy. He has been on follow-up for over a year, and no evidence of local recurrence or metastatic growth. DISCUSSION: Wilms' tumor is the commonest renal tumor of childhood, commonly seen in preschool children. Though it usually happens sporadically, some chromosomal anomalies are known to be associated with it. Patients with congenital anomalies, including spina bifida, are known to have an increased risk of Wilm's tumor. Hence, they need a thorough investigation whenever a visceral lesion is found incidentally, even if they are asymptomatic. CONCLUSION: An intrarenal Wilms tumor can appear synchronously with spina bifida, and a high index of suspicion should be maintained to rule out malignancy when we encounter a young patient with spinal dysraphism and a visceral lesion.