Lipomatosis of the Perirenal Fat: Diagnostic Imaging and Management

Diagnostic Imaging

MRI provides a multiparametric assessment that can help characterize the fatty tissue in patients with lipomatosis of the perirenal fat, and is preferred in younger patients to avoid radiation exposure, according to the American College of Radiology 1, 2, 3
Ultrasound may suggest the diagnosis of lipomatosis of the perirenal fat but is less specific, typically showing hyperechoic areas corresponding to fatty tissue, and is limited in patients with large body habitus 1, 2

Angiomyolipoma (AML) can be differentiated from lipomatosis of the perirenal fat as AMLs contain fat but also vascular elements and smooth muscle, and have fragile vessels that can bleed spontaneously, unlike lipomatosis, as noted by the American College of Radiology 1, 2
Renal cell carcinoma is a critical diagnosis to exclude, especially with fat-poor lesions, and can be distinguished from lipomatosis of the perirenal fat using imaging modalities, according to the American College of Radiology 4, 5
Follow-up imaging is recommended to monitor progression of lipomatosis of the perirenal fat, using the same imaging modality for consistency, as suggested by the American College of Radiology 1