Lumbosacral extrarenal Wilms' tumour:: a case report and literature review

Occurrence of extrarenal Wilms' tumour (WT) is very exceptional and the diagnosis is almost always made after surgical intervention. The tumour can be located in the retroperitoneum, uterus, cervix, testes, skin and even in the thorax. The exact mechanism whereby a WT occurs in extrarenal tissues is not known. The presence of ectopic metanephric blastema cells or the WT gene that cause transformation of extrarenal primitive mesonephric or pronephric remnants into WT are both considered in the embryogenesis. Although ultrasonography and CT scan are both helpful in the definition of retroperitoneal tumours, there is no characteristic finding to diagnose an extrarenal WT before surgery. However the histological characteristics are the same as in intrarenal WT, a retroperitoneal teratoma should be clearly investigated for a possible admixture of WT cells. Patients with extrarenal WT are given the same treatment protocol as patients with stage III WT. In this paper, a 5-year-old female patient with an extrarenal WT located in the lumbosacral region is presented. Conclusion: as a rule, diagnosis of extrarenal Wilms' tumour is made after surgery. Surgical excision is the treatment of choice and the same general therapeutic rules should be followed as when the kidney were affected. Stage III guidelines for chemotherapy and radiotherapy are appropriate in these patients.