title: Tumor detection after inflammation or fibrosis on Mohs levels.
abstract: BACKGROUND
  In Mohs micrographic surgery (MMS), many surgeons will take an additional level based solely on the presence of inflammation or fibrosis.
  
  
  OBJECTIVE
  To determine the frequency with which this occurs and parameters predicting tumor discovery on successive levels.
  
  
  METHODS
  A retrospective study was performed on 22,419 cases treated with MMS between 1996 and May 2011. The surgeons reviewed their own slides in cases where tumor was detected after a level was taken for inflammation or fibrosis.
  
  
  RESULTS
  An additional level was taken for inflammation or fibrosis in 6,233 cases (27.8%), resulting in tumor detection in 121 cases (1.9%). Additional levels were taken for inflammation in 66.6% and fibrosis in 63.0%. Fourteen collision tumors were identified and were preceded by inflammation in 71% of cases.
  
  
  CONCLUSIONS
  Factors that may predict the presence of tumor at subsequent levels include eccentrically placed or shallow first levels failing to completely encompass a previous surgical scar. The presence of dense inflammation may signal an adjacent collision tumor.
  
  
  CONCLUSIONS
  Taking an additional Mohs level when dense inflammation or fibrosis is present may be warranted to ensure complete tumor removal.
authors.affiliation: The Ottawa Hospital, Ottawa, Ontario, Canada. jmacd3@dal.ca
authors.forename: Jillian
authors.initials: J
authors.lastname: Macdonald
authors.forename: Jason R
authors.initials: JR
authors.lastname: Sneath
authors.forename: Bryce
authors.initials: B
authors.lastname: Cowan
authors.forename: David
authors.initials: D
authors.lastname: Zloty
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003872:Dermatitis / Q000473:pathology / Q000601:surgery*; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015580:Mohs Surgery; D010818:Practice Patterns, Physicians'; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery*