An atypical presentation of Wilms tumor as duodenal obstruction in a toddler: a case report and review of literature.

Wilms tumor is the most common primary renal malignancy in children, typically presenting as an asymptomatic abdominal mass in children between 2 and 6 years of age. Duodenal obstruction secondary to direct tumor compression is an exceptionally rare presentation and poses a diagnostic and surgical challenge. We report a 2.5-year-old male who presented with a 1-week history of abdominal pain, abdominal distension, and bilious vomiting. Imaging revealed a large right-sided Wilms tumor causing compression at the duodenojejunal junction. The patient underwent emergency exploratory laparotomy with right radical nephrectomy and Roux-en-Y gastrojejunostomy. Histopathology confirmed Stage III Wilms tumor with favorable histology. The patient recovered well and tolerated subsequent adjuvant chemotherapy and radiotherapy. This case highlights that proximal intestinal obstruction may rarely be the first manifestation of Wilms tumor. Although neoadjuvant chemotherapy before surgical excision constitutes the standard treatment approach at our institution, upfront surgical resection was undertaken to relieve the duodenal obstruction.