title: Diagnosis of Renal Angiomyolipomas: Classic, Fat-Poor, and Epithelioid Types.
abstract: With the increasing discovery of small renal masses with cross-sectional imaging, there has been the concomitant rise in their treatment. With the intent of early curative surgery for a presumed renal cell carcinoma, many renal masses are being resected at surgery without a confirmed diagnosis. Many of them are benign, and some are angiomyolipomas. The diagnosis of renal angiomyolipoma using imaging is, therefore, is as important as ever. Although most, if not all angiomyolipomas with abundant fat are diagnosed readily, some have too little fat to be detected with imaging. This article reviews the current classification, imaging pitfalls, and diagnosis of angiomyolipoma with an emphasis on the fat-poor types. Proper imaging technique, a thorough search for fat, and the appropriate use of percutanoeus biopsy are all needed to eliminate the unnecessary treatment of these benign neoplasms.
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan. Electronic address: jinzaki@rad.med.keio.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Jinzaki
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, MA.
authors.forename: Stuart G
authors.initials: SG
authors.lastname: Silverman
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Akita
authors.affiliation: Department of Diagnostic Pathology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Mikami
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Oya
mesh_terms: D018207:Angiomyolipoma / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed