Retroperitoneal extrarenal angiomyolipoma at the surgical bed 8 years after a renal angiomyolipoma nephrectomy: A case report and review of literature.

Retroperitoneal extrarenal angiomyolipoma (RERAML) are rare and close mimickers of retroperitoneal liposarcoma on both imaging and histopathology. However, imaging findings including heterogeneity, hyperdensity on unenhanced computed tomography, intralesional hemorrhage, absence of calcifications, low signal intensity on T2-weighted magnetic resonance imaging, and dilated intratumoral vessels can lead to the diagnosis of RERAML. Diagnosis of RERAML can avoid unnecessary surgery since conservative medical management with continued surveillance has been proven to be effective for RERAML whereas surgical resection is the treatment for liposarcoma. Imaging and laboratory follow-up for at least 5 years has been recommended in patients who underwent surgical resection of angiomyolipoma (AML). We present a case of RERAML in an asymptomatic patient whose AML recurred in the surgical bed 8 years after an ipsilateral nephrectomy for renal AML.