title: The Accuracy of Measurements of Nonmelanoma Skin Cancer Sizes Referred to the Mohs Surgery Clinic.
abstract: BACKGROUND
  Tumour size is a crucial factor used to plan Mohs procedures. Larger tumours require more time and stages of excision, and they need to be triaged as a higher priority. Therefore, the accuracy in measurement of tumour size is critical.
  
  
  OBJECTIVE
  To investigate if there is a significant difference in accuracy of tumour measurements in referrals between dermatologists and nondermatologists.
  
  
  METHODS
  Performed a retrospective study of 180 referrals from dermatologists and 47 referrals from nondermatologists to The Ottawa Hospital Riverside Mohs Surgery Clinic. We compared the mean size difference of tumours between the preoperative size and the size reported on referral.
  
  
  RESULTS
  Average reported size upon referral of nonmelanoma skin cancer (NMSC) was 1.39 cm2and 1.35 cm2from dermatologists and nondermatologists, respectively ( P = .881). During the preoperative assessment, tumour sizes were 0.65 cm2and 1.45 cm2larger than that reported from dermatologists and nondermatologists, respectively ( P < .05). The duration between referral and preoperative assessment was 3 to 4 months for both groups ( P = .26).
  
  
  CONCLUSIONS
  The accuracy of tumour measurements between dermatologists and nondermatologists differed significantly, as nondermatologists underestimated the size of NMSCs. This directly affects triaging patients and operative management in Mohs surgery. To compensate for size underestimation, early and prompt referrals of NMSCs from nondermatologists are warranted.
authors.affiliation: 1 Division of Dermatology, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Derek
authors.initials: D
authors.lastname: To
authors.affiliation: 1 Division of Dermatology, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Jillian
authors.initials: J
authors.lastname: Macdonald
mesh_terms: D000368:Aged; D000072085:Dermatologists / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D015580:Mohs Surgery / Q000706:statistics & numerical data*; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery
keywords: Mohs; accuracy; nondermatologist; nonmelanoma skin cancer; referral