title: Correlation of Inflammation in Frozen Sections With Site of Nonmelanoma Skin Cancer.
abstract: OBJECTIVE
  During Mohs micrographic surgery of nonmelanoma skin cancer (NMSC), inflammation in histologic frozen sections has been found to occasionally presage the detection of tumors in frozen sections of adjacent excision specimens.
  
  
  OBJECTIVE
  To quantify the correlation between the location of inflammation without visible tumor in histologic frozen sections and the location of subsequently detected NMSC.
  
  
  METHODS
  A retrospective cohort study of 3148 cases pertaining to frozen sections associated with the staged excision of NMSC was performed from September 8, 2008, to September 18, 2009, at an urban academic medical center, with the collected data analyzed on May 9, 2013.
  
  
  METHODS
  Consecutive cases of Mohs micrographic surgery performed at an academic medical center.
  
  
  METHODS
  For each wedge-shaped tissue segment corresponding with 1 hour of time on a clock face, the proportion of patients with inflammation at the source location of the segment who subsequently had a tumor at this same location; the proportion of patients who had neither inflammation nor subsequent tumor at the source location of the segment; the probability of subsequent tumor at this location given the prior finding of inflammation at the same location; and the probability that a location was without tumor in the absence of preexisting inflammation at that location.
  
  
  RESULTS
  Of the medical records of 3148 cases of NMSC that were reviewed, 60 showed inflammation in histologic frozen sections from an excision specimen that was followed by tumor in the subsequent excision specimen. Of these 60, 39 (65%) were b asal cel carcinoma and 21 (35%) were squamous cell carcinomas; 53 (88%) were Mohs stage 1. In 7 of 12 segments, a significant positive correlation was found between the presence of inflammation and the presence of nearby tumor with correlation coefficients ranging from 0.196 to 0.384 (P < .05) . The probability that tumor was absent when inflammation was not seen at a particular location (ie, clock-face segment) in preceding sections from that location was 91%, with segment-specific probability values ranging from 82% to 96%.
  
  
  CONCLUSIONS
  During Mohs micrographic surgery of NMSC with the examination of frozen sections, histologic inflammation is modestly predictive of adjacent tumor whereas lack of inflammation strongly predicts that no additional tumor will be found.
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois2Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois3Department of Surgery, Feinberg School of Medicine, No.
authors.forename: Murad
authors.initials: M
authors.lastname: Alam
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Misbah
authors.initials: M
authors.lastname: Khan
authors.affiliation: Emory University School of Medicine, Atlanta, Georgia5Baptist Health South Florida, Miami.
authors.forename: Emir
authors.initials: E
authors.lastname: Veledar
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Marisa
authors.initials: M
authors.lastname: Pongprutthipan
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Arthur
authors.initials: A
authors.lastname: Flores
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Meghan
authors.initials: M
authors.lastname: Dubina
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Michael
authors.initials: M
authors.lastname: Nodzenski
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Yoo
mesh_terms: D000046:Academic Medical Centers; D002280:Basal Cell Carcinoma / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D015331:Cohort Studies; D005629:Frozen Sections; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D015580:Mohs Surgery; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*