Rare giant renal angiomyolipoma in a 2-year-old female: a case report

Renal angiomyolipoma (AML) is a benign renal tumor that is uncommon in early childhood, particularly in giant form. We report a 2-year-old girl who presented with progressive abdominal distension, constipation, and vomiting for two months. Examination revealed pallor and a large left-sided abdominal mass, with hemoglobin of 8 g/dl (11-14g/dl). Contrast-enhanced CT showed a 15×12×11 cm [CC×AP×TR] mass arising from the left kidney with areas of fat attenuation and additional fat-density foci in the left renal sinus. Due to the patient's young age and the large size of the renal mass, a preoperative Tru-cut biopsy was performed to establish the tissue diagnosis and guide definitive management. Histopathology demonstrated thick-walled blood vessels, smooth muscle bundles, and nests of clear cells without mitotic figures or necrosis. Immunohistochemistry was positive for HMB-45 and Cathepsin K and negative for cytokeratin and Ki-67, supporting the diagnosis of AML. After correction of anemia and preoperative optimization, the patient underwent left nephrectomy with complete tumor excision and had an uncomplicated postoperative recovery. This case highlights the exceptional rarity of giant renal AML in a very young child and emphasizes considering AML in large pediatric renal masses, particularly when fat-containing components are identified on imaging.