Kurt Zimmerman(1,*), Frederic Almy(2), Geoff Saunders(1), Mark Crisman(3) and Leonardo Leonardi(4)
1- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech University, Blacksburg, Virginia 24061, USA
2- Covance Laboratories Inc, Cincinnati, OH 45229, USA
3- Department of large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech University, Blacksburg, Virginia 24061, USA
4- University of Perugia, Department of Veterinary Medicine, 06126 Perugia, Italy
Fine needle aspiration and tissue biopsy samples were taken from a subcutaneous mass in the cranial stifle region of a 10-year-old horse. Key cytologic features included: numerous mildly to moderately pleomorphic histiocytic cells admixed with mononuclear inflammatory cells, occasional fibroblasts, multinucleated cells, and hemosiderin-laden macrophages. Based on these features, cytologic differentials included granulomatous inflammation with reactive fibroplasia, histiocytic sarcoma, giant cell tumor of soft parts and giant cell tumor of bone. The tissue biopsy supported a diagnosis of superficial giant cell tumor of soft parts. This neoplasm is of controversial origin but generally considered to be a soft tissue sarcoma and classified in the World Health Organization classification of tumors under fibrous histiocytic tumors as a giant cell tumor of soft tissue with low risk of malignancy. When found in the subcutis, this neoplasm rarely metastasizes in the horse and has a low rate of local reoccurrence. In this case there was no local recurrence of the tumor after six months after which the horse was lost to follow-up.
Keywords: Cytology, Equine, Giant Cell Tumor of Soft Parts, Histopathology.
Cite this paper:
Zimmerman, K., Almy, F., Saunders, G., Crisman, M. and Leonardi, L. 2019. An unusual case of giant cell tumor of soft parts in an American
Warmblood horse. Open Vet. J. 9(1), 44-48.