Abstract
BACKGROUND: Wilms tumour (WT) represents the most frequent kidney malignant tumour in the paediatric population and is occasionally linked to specific congenital syndromes. Treatment typically includes multimodal therapy consisting of chemotherapy, surgery and/or radiotherapy (RT), with a success rate of approximately 90%. The incidence of nephrotic-nephritic syndrome following unilateral nephrectomy is extremely rare; however, certain long-term kidney complications have been documented. CASE REPORT: A 5-year-old female was diagnosed with WT, Stage 3 with favourable histology. She underwent left radical nephrectomy with preoperative spillage and received RT for the whole abdomen followed by chemotherapy. She was complaint from insidious onset fever, shortness of breath, progressive generalized oedema, reddish urine and headache, occurring 5 days from the 5(th) cycle of chemotherapy and investigation confirm diagnosis of nephrotic-nephritic syndrome. CONCLUSION: Kidney injury poses a risk in cases following nephrectomy, with hyperfiltration, treatment toxicity and immune effects contributing to the condition. Early detection and management are essential for kidney preservation.