title: The 3-dimensional structure of isolated and small foci of prostatic adenocarcinoma: the morphologic relationship between prostatic adenocarcinoma and prostatic intraepithelial neoplasia.
abstract: BACKGROUND
  Transitional histopathologic changes from high-grade prostatic intraepithelial neoplasia (HGPIN) into early prostatic adenocarcinoma (PAC) have not been well studied to date. To investigate the histogenesis of PAC, we examined isolated and small foci of PAC (ISPAC) found in prostatectomy specimens and the 3-dimensional structure of these foci.
  
  
  METHODS
  Twelve consecutive radical prostatectomy specimens having ISPAC, performed for peripheral zone PAC (10 cases) and for transitional zone PAC (2 cases), of Gleason score were studied. One to 2 tissue blocks with representative sections were used.
  
  
  RESULTS
  Eight ISPAC, with Gleason score 3 + 3 had complete serial sections of the entire lesion. PAC consisted of continuous, tortuous and branching tubules and acini arising from benign ducts displaying: (a) HGPIN in 5 ISPAC and (b) no HGPIN in 3 ISAPC. At the junctions between benign epithelia with or without HGPIN and malignant epithelia, there were transitional lesions with HGPIN involving small ducts and acini.
  
  
  CONCLUSIONS
  PAC develops as a result of multiple outpouchings of the epithelium with formation of small ducts and acini showing cytologic atypia and gradual or abrupt loss of basal cells. Grade 3 ISPAC consists of a system of continuous duct pushing into the stroma. There is also evidence suggestive of HGPIN as being both a precursor lesion and an accompanying lesion of PAC.
authors.affiliation: Division of Anatomical Pathology, Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Civic Campus and University of Ottawa, Ontario, Canada. ktmai@ottawahospital.on.ca
authors.forename: Kien T
authors.initials: KT
authors.lastname: Mai
authors.forename: Bruce F
authors.initials: BF
authors.lastname: Burns
authors.forename: William A
authors.initials: WA
authors.lastname: Stinson
authors.forename: Christopher
authors.initials: C
authors.lastname: Morash
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011470:Prostatic Hyperplasia / Q000473:pathology; D019048:Prostatic Intraepithelial Neoplasia / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*