Objective: This study aimed to describe the computed tomographic (CT) imaging appearance of renal epithelioid angiomyolipomas (eAMLs).
Methods: The CT scans and electronic medical records of 8 patients with histologically confirmed eAMLs identified by biopsy and/or surgical excision who had available imaging performed between 1995 and 2012 were reviewed. Preoperative CT imaging appearance, histologic features, and clinical follow-up were recorded for each patient.
Results: Macroscopic fat was identified in 3 (38%) of 8 eAMLs on preoperative CT imaging. Seven of the eAMLs demonstrated postcontrast enhancement of greater than 20 Hounsfield units. None of the eAMLs showed evidence of local invasion, vascular involvement, or distant metastases on the initial preoperative CT; however, 1 patient developed local recurrence and another developed distant metastatic disease on follow-up imaging.
Conclusions: Epithelioid angiomyolipomas may or may not demonstrate macroscopic fat. Those with macroscopic fat do not possess any CT imaging characteristics that allow them to be distinguished from typical angiomyolipomas. Epithelioid angiomyolipomas without macroscopic fat are indistinguishable from renal cancers.
From the *Departments of Radiology, †Urology, and ‡Pathology, University of Michigan Hospitals, Ann Arbor, MI.
Received for publication May 31, 2013; accepted July 29, 2013.
Reprints: Isaac R. Francis, MD, University Hospital Floor B1 Room D408, 1500 E Medical Center Dr, Ann Arbor, MI 48109 (e-mail: firstname.lastname@example.org).
Richard H. Cohan, MD, is a consultant to General Electric Healthcare and has received royalties from Wolters Kluwer and Taylor and Francis. Matthew S. Davenport, MD, is a consultant to the Food and Drug Administration. For the remaining authors, no conflicts of interest were declared.