Evaluation of a two-centimeter lateral surgical margin for excision of grade I and grade II cutaneous mast cell tumors in dogs.
OBJECTIVE
To evaluate completeness of excision and clinical outcome in dogs with cutaneous mast cell tumors (MCTs) excised with a lateral margin of 2 cm and a deep margin of 1 fascial plane.


METHODS
Prospective study.


METHODS
16 client-owned dogs with 1 or more cutaneous MCTs.


METHODS
Excision of MCTs was performed with a 2-cm lateral margin and a deep margin of 1 fascial plane. Histologic tumor grading was performed; surgical margins were categorized as complete or incomplete. Follow-up information was obtained via repeat examination of the dogs by veterinarians or client-completed questionnaires.


RESULTS
4 grade I and 19 grade II cutaneous MCTs were evaluated. Overall, 21 (91%) MCTs were completely excised; 2 grade II tumors had foci of mast cells at the 2-cm margin. Two dogs received adjunctive treatments following surgery. Follow-up information was available for all dogs (median follow-up period, 379 days; range, 51 to 538 days); no local recurrence was detected during this time. De novo MCTs were detected in 3 of 16 dogs at 37, 54, and 154 days after surgery. Via Kaplan-Meier analysis, median survival time and disease-free interval were both > 538 days (medians not yet reached). No prognostic variables were identified.


CONCLUSIONS
Excision with a 2-cm lateral margin and a deep margin of 1 fascial plane may result in satisfactory excision of grades I and II MCTs in dogs, with recurrence rates similar to those reported previously. Use of these margins may minimize complications associated with larger local tumor resection.
Fulcher
Ryan P
RP
Department of Surgery, The Animal Medical Center, 510 E 62nd St, New York, NY 10021, USA.
Ludwig
Lori L
LL
Bergman
Philip J
PJ
Newman
Shelley J
SJ
Simpson
Amelia M
AM
Patnaik
Amiya K
AK
D000818:Animals; D018572:Disease-Free Survival; D004283:Dog Diseases / Q000473:pathology / Q000601:surgery*; D004285:Dogs; D005260:Female; D008297:Male; D012515:Mast-Cell Sarcoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D009364:Neoplasm Recurrence, Local / Q000662:veterinary; D009367:Neoplasm Staging / Q000662:veterinary*; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D016019:Survival Analysis; D016896:Treatment Outcome