title: Assessment of histopathological features of needle biopsy in recurrent prostate cancer following salvage high-intensity focused ultrasound.
abstract: BACKGROUND
  Local recurrence of prostate cancer (PCa) following radiotherapy may be treated with curative intent using salvage high-intensity focused ultrasound (s-HIFU). The interpretation of needle core biopsy specimens following s-HIFU is a daunting task, even for experienced pathologists. We describe various histopathological features encountered in biopsy specimens following whole-gland s-HIFU in one of the largest descriptive studies to date.
  
  
  METHODS
  Fifty-five patients with biopsy-proven localized radio-recurrent PCa underwent s-HIFU and transrectal ultrasound (TRUS)-guided prostatic needle biopsies at 180 days post-treatment. All biopsies were reviewed by two genitourinary pathologists.
  
  
  RESULTS
  PCa was detected in 11 (24%) biopsies. Radiation therapy-associated changes were identified in all cases. Additional findings included extensive coagulative stromal necrosis (100%), smudgy chromatin of cancer nuclei (82%), and markedly enlarged bizarre nuclei in the residual cancer (55%). Gleason grade assignment was possible in 10 (91%) of these biopsies and concordance of Gleason grading between pre- and post-therapy specimens was observed in six (60%) cases.
  
  
  CONCLUSIONS
  The histological interpretation of needle biopsies following salvage HIFU is challenging and requires an understanding of the histopathological changes associated with this procedure in both tumoural and non-tumoural prostatic tissue. Accurate interpretation of the morphological changes following s-HIFU is instrumental for optimization of clinical decision-making and treatment planning in recurrent PCa.
authors.affiliation: Department of Surgery, Division of Urologic Oncology, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Michele
authors.initials: M
authors.lastname: Billia
authors.affiliation: Department of Surgery, Division of Urologic Oncology, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Khurram M
authors.initials: KM
authors.lastname: Siddiqui
authors.affiliation: Department of Pathology and Laboratory Medicine, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Susanne
authors.initials: S
authors.lastname: Chan
authors.affiliation: Department of Surgery, Division of Urologic Oncology, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Fan
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Urology, University of Dammam, Dammam, Saudi Arabia.
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Zahrani
authors.affiliation: Department of Pathology and Laboratory Medicine, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Gomez
authors.affiliation: Department of Surgery, Division of Urologic Oncology, London Health Sciences Centre, Western University, London, ON, Canada.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Chin