title: Imaging of uncommon retroperitoneal masses.
abstract: Retroperitoneal masses not arising from major solid organs are uncommon. Although there is no simple method of classifying retroperitoneal masses, a reasonable approach is to consider the masses as predominantly solid or cystic and to subdivide these into neoplastic and nonneoplastic masses. Because the treatment options vary, it is useful to be able to differentiate these masses by using imaging criteria. Although the differential diagnosis of retroperitoneal masses can be narrowed down to a certain extent on the basis of imaging characteristics, patterns of involvement, and demographics, there is still a considerable overlap of imaging findings for these masses, and histologic examination is often required for definitive diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging play an important role in characterization and in the assessment of the extent of the disease and involvement of adjacent and distant structures. Familiarity with the CT and MR imaging features of various retroperitoneal masses will facilitate accurate diagnosis and staging for aggressive lesions.
authors.affiliation: Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. radprabhakar@gmail.com
authors.forename: Prabhakar
authors.initials: P
authors.lastname: Rajiah
authors.forename: Rakesh
authors.initials: R
authors.lastname: Sinha
authors.forename: Carlos
authors.initials: C
authors.lastname: Cuevas
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Dubinsky
authors.forename: William H
authors.initials: WH
authors.lastname: Bush
authors.forename: Orpheus
authors.initials: O
authors.lastname: Kolokythas
mesh_terms: D003560:Cysts / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010532:Peritoneal Diseases / Q000175:diagnosis*; D035583:Rare Diseases / Q000175:diagnosis; D012187:Retroperitoneal Space / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*