title: Focal positive prostate-specific membrane antigen (PSMA) expression in ganglionic tissues associated with prostate neurovascular bundle: implications for novel intraoperative PSMA-based fluorescent imaging techniques.
abstract: OBJECTIVE
  Prostate specific membrane antigen (PSMA) is primarily expressed in glandular prostatic tissue and is frequently utilized to detect primary or metastatic prostatic adenocarcinoma (CaP). A purported novel application of PSMA detection is the intraoperative real-time identification of CaP using radioimmunoscintigraphy to define the extension of the surgical resection. Considering that PSMA expression has been reported in other tissues, we evaluated its immunoexpression in prostatic neurovascular bundle elements to assess the convenience and safety of the aforementioned procedure.
  
  
  METHODS
  Twenty consecutive specimens of radical prostatectomy (RP) were retrieved from our surgical pathology archives. PSMA immunoexpression (Clone 3E6, DAKO) was assessed in a representative section from each specimen containing neurovascular bundle elements.
  
  
  RESULTS
  PSMA expression was documented in 20/20 of examined CaP slides. Most cases exhibited an apical/cytoplasmic or cytoplasmic with membranous accentuation pattern of staining. Focal weak to moderate cytoplasmic staining was detected in associated ganglionic tissue in 3/15 of the examined RP. In all cases, staining was cytoplasmic, less extensive, and weaker than the pattern observed in CaP. None of the peripheral nerve sheath cells or lymphovascular components of the examined neurovascular bundles were positive for PSMA.
  
  
  CONCLUSIONS
  We found focal positive PSMA expression in the ganglionic cells of the prostatic neurovascular bundle. Our results suggest that the radioimmunoscintigraphic detection of radiolabeled PSMA antibodies might not be entirely specific for prostatic cells; this observation must be taken into account should an intraoperative PSMA-based fluorescent imaging technique be used to define the extension of the surgical procedure.
authors.affiliation: Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
authors.forename: Alcides
authors.initials: A
authors.lastname: Chaux
authors.forename: John
authors.initials: J
authors.lastname: Eifler
authors.forename: Sarah
authors.initials: S
authors.lastname: Karram
authors.forename: Turki
authors.initials: T
authors.lastname: Al-Hussain
authors.forename: Sheila
authors.initials: S
authors.lastname: Faraj
authors.forename: Martin
authors.initials: M
authors.lastname: Pomper
authors.forename: Ronald
authors.initials: R
authors.lastname: Rodriguez
authors.forename: George J
authors.initials: GJ
authors.lastname: Netto
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000601:surgery; D000954:Antigens, Surface / Q000096:biosynthesis*; D003593:Cytoplasm / Q000378:metabolism; D005240:Feasibility Studies; D045888:Ganglion Cysts / Q000378:metabolism*; D043425:Glutamate Carboxypeptidase II / Q000096:biosynthesis*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D011467:Prostate / Q000098:blood supply / Q000294:innervation / Q000378:metabolism*; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D016719:Radioimmunodetection / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D000954:Antigens, Surface; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II