Intrarenal neuroblastoma: a diagnostic challenge.

Abdominal masses in children are usually retroperitoneal in location and 50% are renal in origin. In infants less than 2 months, majority of renal masses are benign; frequency of malignancy increases with age. Wilms'tumor is the commonest solid intrarenal tumors. However, occasionally neuroblastoma occurs in the kidney. Neuroblastoma in 50% of cases presents before 2 years of age, and 75% before 4 years. Neuroblastomas can occur anywhere along the neuroectodermal sympathetic chain, although adrenal medulla is the commonest site (50 - 70%). Intrarenal neuroblastoma is a rare clinical diagnosis. It clinically and radiologically mimics Wilms'tumor and it is difficult to differentiate between the two preoperatively. Lung metastasis and vascular invasion are also rare in neuroblastoma but rather common in Wilms'tumor. We present case of a patient who had extensive renal involvement with neuroblastoma and pulmonary metastasis, clinically and radiologically it was difficult to differentiate between the Wilms'tumor and neuroblastoma.