title: [Perirenal malignant perivascular epithelioid cell tumor originating from right retroperitoneum: a case report].
abstract: A 51-year-old woman was admitted to our hospital for detailed examinations and medical treatment against the right retroperitoneum tumor and liver lesions. Computed tomography showed a 20 cm diameter enhanced mass in the right perirenal space and multiple liver metastases. Pathological examination by needle biopsy revealed a perivascular epithelioid cell tumor (PEComa). With weekly administration of a mTOR inhibitor, Temsirolimus, the tumor was reduced by about 20% one month later. The maximal response was stable disease due to RECIST v 1. 1. However, shortly after the minimal response, the disease showed progression. She died about five months after the start of molecular targeted therapy. In regard to the origin of PEComa, our report is the fifth in Japan as a case of retroperitoneal origin to the best of our knowledge.
authors.affiliation: The Department of Urology, Graduate School of Medicine, University of the Ryukyus.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Nakanishi
authors.affiliation: The Department of Urology, Graduate School of Medicine, University of the Ryukyus.
authors.forename: Minoru
authors.initials: M
authors.lastname: Miyazato
authors.affiliation: National Cancer Center Hospital, Mammary Gland and Oncology.
authors.forename: Kan
authors.initials: K
authors.lastname: Yonemori
authors.affiliation: The Department of Pathology and Oncology, Graduate School of Medicine, University of the Ryukyus.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tamashiro
authors.affiliation: The Department of Pathology and Oncology, Graduate School of Medicine, University of the Ryukyus.
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshimi
authors.affiliation: The Department of Urology, Graduate School of Medicine, University of the Ryukyus.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Saito
mesh_terms: D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000473:pathology*; D054973:Perivascular Epithelioid Cell Neoplasms / Q000473:pathology*; D012187:Retroperitoneal Space