title: [Extrarenal Retroperitoneal Angiomyolipoma Masquerading as Retroperitoneal Liposarcoma : A Report of Two Cases].
abstract: We report two patients with extrarenal retroperitoneal angiomyolipoma masquerading as perinephric liposarcoma. Patient 1 : A 66-year-old man was diagnosed with a retroperitoneal tumor near the right renal hilum on an abdominal computed tomography (CT) performed before surgery for gastric cancer. A diagnosis of extrarenal retroperitoneal angiomyolipoma was made on the basis of negative uptake of fluorine- 18 2-deoxy-2-fluoro-D-glucose positron emission tomography (18F-FDG PET)/CT. However, because the tumor was found to have gradually enlarged at 18 months afterward, he underwent resection of the extrarenal fat tissue together with the right kidney. Patient 2 : A 56-year-old man underwent abdominal ultrasound during a periodic medical examination, which revealed a right retroperitoneal tumor. Because of the findings in the contrast-enhanced CT and positive uptake of 18F-FDG PET/CT, he underwent resection of the extrarenal fat tissue together with the right kidney. The pathological examination of the two tumors confirmed extrarenal angiomyolipoma. The differential diagnosis of extrarenal retroperitoneal angiomyolipoma from retroperitoneal liposarcoma is difficult even with the use of 18F-FDG PET/CT.
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yamamoto
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Inoue
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Numakura
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuruta
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Maeno
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Saito
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Narita
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Tsuchiya
authors.affiliation: Center for Kidney Disease and Transplantation, Akita University Hospital.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Satoh
authors.affiliation: The Department of Urology, Akita University Graduate School of Medicine.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Habuchi
mesh_terms: D000368:Aged; D018207:Angiomyolipoma / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008080:Liposarcoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D012186:Retroperitoneal Neoplasms / Q000000981:diagnostic imaging*
chemical_list: D019788:Fluorodeoxyglucose F18