title: Quantification of surgical margin length changes after excision of feline injection site sarcomas-A pilot study.
abstract: OBJECTIVE
  To evaluate degree length change of lateral surgical margins at various stages of processing for histological examination and quantify the length change between grossly normal surgical margins (GNSM) and pathologist-reported histologic tumor-free margin (HTFM) in widely resected feline injection site sarcoma (FISS) specimens.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  Five client-owned cats with injection site sarcomas.
  
  
  METHODS
  All cats underwent wide surgical excision (35-55 mm gross lateral margins, 2 fascial planes deep). Gross normal lateral margin measurements from tumor edge were recorded in 4 directions (cranial, caudal, dorsal, ventral) at 5 time points: intra-op (in vivo GNSM); immediately following excision (ex vivo GNSM); following formalin fixation (post-fixation GNSM); after trimming and mounting on glass slides (on-slide GNSM); and HTFM at the narrowest point from the HTFM from the same slides used for on-slide GNSM. Percent change in lateral margin length from in vivo measurements was quantified at each time point and compared using 1-way repeated measures ANOVA.
  
  
  RESULTS
  The largest mean decrease in percent GNSM length occurred immediately after excision (in vivo to ex vivo GNSM = 29%; P = .016). Formalin fixation, trimming, and mounting on slides did not result in additional significant changes in length. Mean HTFM length was significantly decreased compared to both in vivo GNSM (33%; P = .014) and on-slide GNSM (7%; P = .024).
  
  
  CONCLUSIONS
  Significant decreases in surgical margin length in FISS specimens occur immediately following excision (prior to formalin fixation). Subgross evaluation of tumor-free margins from on-slide GNSM to HTFM overestimates the actual (histologic) tumor-free margins.
authors.affiliation: Departments of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Jesse L
authors.initials: JL
authors.lastname: Terry
authors.affiliation: Departments of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Milan
authors.initials: M
authors.lastname: Milovancev
authors.affiliation: Departments of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Sarah
authors.initials: S
authors.lastname: Nemanic
authors.affiliation: Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Christiane V
authors.initials: CV
authors.lastname: Löhr
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000473:pathology / Q000601:surgery*; D002415:Cats; D005260:Female; D008297:Male; D000072662:Margins of Excision; D010865:Pilot Projects; D011446:Prospective Studies; D012509:Sarcoma / Q000601:surgery / Q000662:veterinary*; D012878:Skin Neoplasms / Q000601:surgery / Q000662:veterinary*; D016707:Tissue Fixation