title: Fibrosarcoma over the tarsal groove of a 14-month-old Quarter horse.
abstract: A 14-month-old male Quarter horse was presented for evaluation of a grade 3 out of 5 (grade 0 = sound; grade 5 = non-weight bearing) right rear lameness. A firm, 8 x 16 cm mass was palpable at the caudal medial aspect of the distal tibia and proximal tarsal region of the right hind limb. A percutaneous needle aspirate contained mesenchymal cells that were moderate to large in size with single, oblong nuclei. Differential diagnoses included fibrous hyperplasia, fibroma, or well-differentiated fibrosarcoma. Excisional biopsy for both definitive diagnosis and treatment was offered and selected by the owner. A fibrosarcoma was confirmed by histological examination of the mass. One and a half years after resection signs of lameness or evidence of regrowth of the mass were not evident.
authors.affiliation: Kansas State University, Veterinary Medical Teaching Hospital, Manhattan, Kansas, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Story
authors.forename: E M
authors.initials: EM
authors.lastname: Gaughan
authors.forename: G A
authors.initials: GA
authors.lastname: Andrews
authors.forename: S
authors.initials: S
authors.lastname: Balch
mesh_terms: D000818:Animals; D044963:Biopsy, Fine-Needle / Q000662:veterinary; D005354:Fibrosarcoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D006734:Horse Diseases / Q000473:pathology* / Q000601:surgery*; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D007794:Lameness, Animal / Q000209:etiology / Q000473:pathology; D008297:Male; D012983:Soft Tissue Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome