A 2-Year-Old Child with Progressive Abdominal Distension: What's Your Diagnosis

A 2-year-old male child presents with progressive abdominal distension for 2 months, intermittent fever, weight loss, and decreased appetite. There is no history of trauma. On examination: * Firm, non-tender left abdominal mass crossing the midline. * Mild pallor. Imaging Findings Ultrasound Abdomen * Large heterogeneous left renal mass measuring 9 × 8 × 7 cm. * Internal cystic areas with vascularity. * Left kidney architecture is distorted. * Mild hydronephrosis. * Few enlarged para-aortic lymph nodes. * No focal liver lesions. Contrast-Enhanced CT Abdomen * Large heterogeneously enhancing left renal mass with areas of necrosis. * No evidence of tumor thrombus. * Para-aortic lymphadenopathy present. * No contralateral renal involvement. CT Chest * Multiple bilateral pulmonary nodules suggestive of metastatic deposits. Questions 1. What is the most likely diagnosis? 2. What are the common differential diagnoses of a renal mass in childhood? 3. Which genetic syndromes are associated with this condition? 4. What staging system is commonly used for this tumor? 5. What pre-treatment investigations should be performed? 6. What is the standard treatment approach for this condition? 7. What are the common sites of metastasis? 8. Which clinical and pathological features are associated with a poor prognosis? 9. What are the major histopathological subtypes of this tumor? 10. What is the expected survival rate for patients with localized disease?