Giant renal angiomyolipoma: unusual cause of huge abdominal mass

We present the imaging and histopathological characteristics of a giant renal angiomyolipoma (AML) in a 49-year-old female patient, who presented with bloating sensation in the abdomen and a steadily increasing abdominal girth for about 3 years. Contrast enhanced computed tomography (CECT) scan films of abdomen revealed that a large fat containing tumor had replaced the left kidney while displacing the rest of the abdominal contents toward the other side of the midline. Intraoperatively the left kidney was completely replaced by a fat containing tumor. The recovered surgical specimen measured 39 cm × 25 cm × 9 cm and weighed 7500 g. Histopathological investigation with immuno-histochemical staining of the specimen with hydroxy beta-methylbutyric acid-45 confirmed this lesion as AML. CECT scan of the head did not show any lesion suggestive of tuberous sclerosis. The giant tumor of the present case is the heaviest AML in both syndromic and sporadic categories and largest by dimensions as sporadic AML ever reported in the literature.