title: Association of histologic tumor characteristics and size of surgical margins with clinical outcome after surgical removal of cutaneous mast cell tumors in dogs.
abstract: OBJECTIVE
  To evaluate the relationship between width and depth of surgical margins, amount of edema within and around the tumor, and degree of demarcation between the tumor and surrounding tissues with the clinical outcome following surgical removal of cutaneous mast cell tumors (cMCTs) in dogs.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  100 dogs with 115 resectable cMCTs.
  
  
  METHODS
  Information about the dogs' clinical outcomes following cMCT removal was obtained from primary care veterinarians. Histologic sections of excised tumors were assessed retrospectively for tumor grade and measurement of the narrowest lateral and deep margins of nonneoplastic tissue excised with the tumors; edema within the tumor and surrounding tissues was assessed as minimal, moderate, or severe. Tumors were classified as poorly, moderately, or well demarcated on the basis of the degree of mast cell infiltration into the adjoining connective tissue.
  
  
  RESULTS
  Following tumor excision (with no additional postsurgery treatment), 96 dogs had no local recurrence or metastatic disease for 27 to 31 months; 4 metastatic disease-related deaths (dogs with grade II or III tumors) occurred within 3 to 9 months. Histologically, mean lateral and deep surgical margins around the tumors were 8.9 and 5.3 mm, respectively. No recurrence of tumor or metastatic disease developed following excision with lateral margins ≥ 10 mm and deep margins ≥ 4 mm. Edema and degree of demarcation were not correlated with outcome.
  
  
  CONCLUSIONS
  Results suggested that most grade I and II cMCTs in dogs can be successfully treated by complete surgical removal with margins smaller than those currently recommended.
authors.affiliation: Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA. patricia.schultheiss@colostate.edu
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Schultheiss
authors.forename: David W
authors.initials: DW
authors.lastname: Gardiner
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Rao
authors.forename: Francisco
authors.initials: F
authors.lastname: Olea-Popelka
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Tuohy
mesh_terms: D000818:Animals; D015331:Cohort Studies; D004283:Dog Diseases / Q000473:pathology* / Q000601:surgery*; D004285:Dogs; D004487:Edema / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary; D005260:Female; D008297:Male; D012515:Mast-Cell Sarcoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary; D009367:Neoplasm Staging / Q000662:veterinary; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome