title: Alveolar soft-part sarcoma of the retroperitoneum.
abstract: A 33-year-old woman was referred to Iida Municipal Hospital because of left back pain. Computed tomography showed a tumor (17 x 11 x 10 cm) in the left retroperitoneal space. T1- and T2-weighted magnetic resonance imaging showed an inhomogeneous mass with marginal blood vessels. The tumor was resected via lumbar oblique incision with the thoraco-abdominal approach. The tumor weighed 1800 g and consisted of nests of 5-100 large, loosely arranged, polygonal cells, surrounded by capillaries, resembling alveoli. The tumor cells were rich in cytoplasm, containing periodic acid-Schiff- and diastase-positive granules and typical crystals. The pathological diagnosis was alveolar soft-part sarcoma (ASPS). Alveolar soft-part sarcoma is a rare soft-tissue tumor that accounts for approximately 0.5-1% of soft-tissue sarcomas. Such tumors originating in the retroperitoneal space are extremely rare. Herein is reported a case of ASPS of the retroperitoneum with radiological and pathological findings.
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Masakuni
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishizuka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakayama
authors.forename: Shinya
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Igawa
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishizawa
authors.forename: Kouji
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Toshio
authors.initials: T
authors.lastname: Yamashita
authors.forename: Takaaki
authors.initials: T
authors.lastname: Matsushita
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis*; D018234:Sarcoma, Alveolar Soft Part / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed