Fibrosarcoma adjacent to the site of microchip implantation in a cat

J Feline Med Surg. 2008 Apr;10(2):202-5. doi: 10.1016/j.jfms.2007.10.011. Epub 2008 Mar 3.


A 14-year-old spayed female domestic shorthair cat presented with an interscapular mass. A computed tomography scan, biopsy, and histological examination revealed a fibrosarcoma adjacent to a pet identification microchip. Because the cat was previously vaccinated at this site, it is not possible to establish definitive causation of the fibrosarcoma, but this is the first report of a tumor in the vicinity of a microchip in a cat. Microchip-associated tumors have been reported in rodents and dogs. Veterinarians should be aware that because inflammation may predispose felines to tumor formation, separation and observation of vaccination and implantation sites are indicated. Adherence to American Association of Feline Practitioners (AAFP) vaccination guidelines and monitoring of microchip implantation sites are recommended.

Publication types

  • Case Reports

MeSH terms

  • Animal Identification Systems / veterinary*
  • Animals
  • Cat Diseases / diagnosis*
  • Cat Diseases / pathology
  • Cats
  • Female
  • Fibrosarcoma / diagnosis
  • Fibrosarcoma / etiology
  • Fibrosarcoma / pathology
  • Fibrosarcoma / veterinary*
  • Head and Neck Neoplasms / diagnosis
  • Head and Neck Neoplasms / etiology
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / veterinary*
  • Immunohistochemistry / veterinary
  • Prostheses and Implants / adverse effects
  • Prostheses and Implants / veterinary*
  • Vaccination / adverse effects
  • Vaccination / veterinary*