title: Identification of isolated and early prostatic adenocarcinoma in radical prostatectomy specimens with correlation to biopsy cores: clinical and pathogenetic significance.
abstract: Prostatic adenocarcinoma (PAC) is a multifocal disease. In this study, we identified isolated and small foci of PAC (ISPAC) in radical prostatectomy specimens, described the histopathologic features, investigated their zonal distribution in the prostate and their relationship with large tumor nodules, and correlated the findings with those of preceding biopsy cores. One hundred and thirty radical prostatectomy specimens performed for PAC or for urothelial carcinoma of the urinary bladder with incidental PAC were reviewed for identification of ISPAC. Prostates were serially sectioned in the horizontal plane and submitted in toto for microscopic examination. ISPAC were defined as foci of PAC measuring less than 3 mm in maximum diameter. There were 461 ISPAC identified in 114 cases. They were distributed in the transitional zone (TZ) (18 foci), the apex (73 foci), the anterior horn of the non-TZ (NTZ) (118 foci), the base (8 foci), and the remaining NTZ (244 foci). ISPAC usually consisted of groups of small acini with a GS ranging from 2 to 7 (3 + 4). GSs of ISPAC consisted of single grade or two consecutive grades equal to or lower than those of the main PAC. ISPAC were more often located in close proximity to large tumor nodules. The number of ISPAC increased with the tumor volume up to 3 cm3, then decreased as the PAC became more extensive (p value = 0.02, statistically significant). Prostates with NTZ PAC <1.5 cm3 and TZ PAC or prostates containing 4 or more than 4 ISPAC tended to be frequently associated with small foci of PAC in biopsy cores In this study, we identified ISPAC that likely represent foci of PAC in early development and account for the multicentricity and heterogeneity of PAC. ISPAC in the NTZ were common and may account for small foci of PAC or atypia in biopsy cores. Although these small foci of PAC or atypia in biopsy cores without accompanying higher GS PAC were often associated with significant PAC, they may also occasionally represent insignificant or vanishing PAC in subsequent radical prostatectomies.
authors.affiliation: Division of Anatomical Pathology, Department of Laboratory Medicine, The Ottawa Hospital, Civic Campus, Ottawa, Ontario, Canada. ktmai@ottawahospital.on.ca
authors.forename: Kien T
authors.initials: KT
authors.lastname: Mai
authors.forename: Denise C
authors.initials: DC
authors.lastname: Landry
authors.forename: Hossein M
authors.initials: HM
authors.lastname: Yazdi
authors.forename: William A
authors.initials: WA
authors.lastname: Stinson
authors.forename: D Garth
authors.initials: DG
authors.lastname: Perkins
authors.forename: Christopher
authors.initials: C
authors.lastname: Morash
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy; D019048:Prostatic Intraepithelial Neoplasia / Q000473:pathology* / Q000601:surgery; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery