title: Rheb/mTOR/p70s6k Cascade and TFE3 Expression in Conventional and Sclerosing PEComas of the Urinary Tract.
abstract: Perivascular epithelioid cell tumors (PEComas) are rarely found in the urinary tract. The clinicopathologic characteristics of 10 cases, retrospectively collected from 5 medical institutions in 3 different European countries, are presented in this study. Male/female ratio was 3:7 and the average age at diagnosis was 62.7 years. Nine cases were sporadic and 1 showed germline mutation of the TSC2 gene. Eight cases were located in the kidney, 1 in the left adrenal and 1 in the right ureter. All of the patients were alive and free of disease at the time of last contact (mean follow-up, 14.1 mo). Four cases displayed a conventional morphology and 6 showed a prominent sclerotic stroma. By immunohistochemistry, melanocytic markers were consistently expressed, especially HMB-45 (10 cases), MiTF (9 cases), and Melan-A (6 cases). Desmin was expressed in 6 cases; 2 cases were positive for CD117; a single case showed TFE3 expression. pMAPK, mTOR, and pAKT demonstrated variable immunostaining with focal positivity in 7, 4, and 2 cases, respectively. Cytokeratins were repeatedly negative in all cases. PEComas in the urinary tract, especially in the renal region, may show a relatively high frequency of the sclerosing histologic subtype. Knowledge of the distinct histology and immunohistochemical profile is vital to correctly diagnose this rare entity.
authors.affiliation: *Departments of Pathology General University Hospital, Alicante †Virgen de Valme University Hospital, Sevilla ¶Cruces University Hospital, Biocruces Institute, University of the Basque Country (UPV/EHU), Barakaldo, Spain ‡Dubrava University Hospital, Zagreb, Republic of Croatia §Charles University Hospital, Plzen, Czech Republic ∥Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS.
authors.forename: María
authors.initials: M
authors.lastname: Planelles
authors.forename: Laura
authors.initials: L
authors.lastname: Macías
authors.forename: Gloria
authors.initials: G
authors.lastname: Peiró
authors.forename: Stela
authors.initials: S
authors.lastname: Bulimbasič
authors.forename: Ondrej
authors.initials: O
authors.lastname: Hes
authors.forename: Antonio
authors.initials: A
authors.lastname: Robles
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
authors.forename: Whitney
authors.initials: W
authors.lastname: Davidson
authors.forename: José I
authors.initials: JI
authors.lastname: López
mesh_terms: D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000235:genetics / Q000503:physiopathology; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000172:deficiency / Q000235:genetics; D052177:Kidney Diseases, Cystic / Q000235:genetics / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D054973:Perivascular Epithelioid Cell Neoplasms / Q000235:genetics / Q000503:physiopathology*; D012189:Retrospective Studies; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D014402:Tuberous Sclerosis / Q000235:genetics / Q000503:physiopathology; D014551:Urinary Tract / Q000503:physiopathology; D014571:Urologic Neoplasms / Q000235:genetics / Q000503:physiopathology*
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C069203:TFE3 protein, human; D007371:Interferon-gamma; C546842:MTOR protein, human; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases