title: Depletion of Core Needle Biopsy Cellularity and DNA Content as a Result of Vigorous Touch Preparations.
abstract: BACKGROUND
  Touch preparations (TP) of core needle biopsies (CNBs) are used at some institutions for on-site assessment of CNB adequacy. In our clinical practice, we have encountered instances in which TPs resulted in substantial depletion of CNB cellularity.
  
  
  OBJECTIVE
  To examine the effect of increasingly vigorous TPs on cellularity and DNA content of CNBs.
  
  
  METHODS
  Ex vivo CNBs (n = 56) were performed on resected lung and kidney tumor specimens. For each specimen, CNBs were performed in quadruplicate on tumor and nontumor tissue and subjected to 1 of 4 TP methods: imprint, 1-cm drag, 2-cm drag, or full-slide drag. Overall cellularity in TPs relative to corresponding CNBs was estimated semiquantitatively. DNA was extracted and quantified from 12 TPs and corresponding CNBs. Two cytopathologists performed a blinded diagnostic assessment of Diff-Quik-stained TPs.
  
  
  RESULTS
  Cellularity of imprint, 1-cm, 2-cm, and full-slide TPs represented, on average, 19%, 33%, 41%, and 46% of total CNB cellularity, respectively (p = .003). Average DNA content in imprint, 1-cm, and 2-cm TPs was 0.3 μg (range, 0.1-0.8 μg), 0.4 μg (range, 0.1-1 μg), and 0.6 μg (range, 0.2-1.3 μg), respectively, which represented on average 15%, 36%, and 50%, respectively, of total CNB DNA content. Diagnostic accuracy was not inferior for less-extensive TPs, compared with more-extensive TPs.
  
  
  CONCLUSIONS
  Vigorous TPs may contain a substantial fraction of CNB cellularity and DNA content, whereas more-limited TPs are less disruptive to CNBs but remain suitable for cytologic assessment. We suggest avoiding excessively forceful TPs and, whenever clinically feasible, obtaining additional samples to ensure sufficient cellularity for potential ancillary studies.
authors.forename: Natasha
authors.initials: N
authors.lastname: Rekhtman
authors.forename: Sofia
authors.initials: S
authors.lastname: Kazi
authors.forename: JinJuan
authors.initials: J
authors.lastname: Yao
authors.forename: Snjezana
authors.initials: S
authors.lastname: Dogan
authors.forename: Angela
authors.initials: A
authors.lastname: Yannes
authors.forename: Oscar
authors.initials: O
authors.lastname: Lin
authors.forename: Mikhail
authors.initials: M
authors.lastname: Silk
authors.forename: Tarik
authors.initials: T
authors.lastname: Silk
authors.affiliation: From the Departments of Pathology (Drs Rekhtman, Kazi, Yao, Dogan, and Lin and Ms Yannes);|and Radiology (Drs Silk and Durack and Mr Silk), at Memorial Sloan Kettering Cancer Center, New York, New York.|Drs Rekhtman and Kazi contributed equally to this manuscript.
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Durack
mesh_terms: D062005:Biopsy, Large-Core Needle; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D008175:Lung Neoplasms / Q000473:pathology; D013048:Specimen Handling