Giant Epithelioid Angiomyolipoma: An Imaging-related Differential Diagnosis Among Fat-containing Renal Masses

Renal masses are a common imaging finding and include a broad spectrum of both benign and malignant histopathologic types, with pleomorphic clinical presentation and imaging features. Although differential diagnosis is often challenging, characterization is crucial for appropriate management. Angiomyolipomas typically occur as small and asymptomatic lesions incidentally detected while imaging the abdomen and whose radiologic criterion for diagnosis is the unequivocal presence of macroscopic fat within the lesion. Rare angiomyolipoma subtypes (such as the epithelioid variant) may reach considerable dimensions and show atypical imaging features, turning into a diagnostic conundrum. Multimodality imaging can guide the differential diagnosis of equivocal fat-containing renal masses and allows lesion characterization.