title: Benign giant cell tumour of tendon sheaths in a European Lynx (Lynx lynx).
abstract: The histological, histochemical, immunohistochemical and ultrastructural features of a benign giant cell tumour (BGCT) of tendon sheaths in a 12-year-old male European lynx (Lynx lynx) are reported herein. The neoplastic mass involved the subcutaneous and inter-muscular tissues of the first, second, third and fourth digit of the left forelimb, from the phalanxes up to the carpus. The tumour appeared as a grey-whitish tissue mottled with darker areas, along with several scattered foci of orange colour. Histologically, the lesion consisted of a mixed population of numerous, multinucleated giant cells and epithelioid or spindle-shaped mononuclear cells embedded in a loose, highly vascular stroma. Neoplastic cells lined cleft formations and synovial-like projections into cystic spaces. No osteoid matrix could be detected. Haemorrhage and necrosis were also observed. The mononuclear and the giant cells were tartrate-resistant acid phosphatase and periodic acid-Schiff positive, being also immunohistochemically reactive for lysozyme and vimentin, with a few cells showing immunopositivity also for alpha-1-antitrypsin. Ultrastructurally, histiocyte-like cells, fibroblast-like cells and multinucleated giant cells were observed, but no virus-like particles could be detected in any of the above cell types. The BGCT of tendon sheaths, a fairly uncommon neoplasm in animals, has not been previously reported in the lynx.
authors.affiliation: Department of Comparative Biomedical Sciences, Faculty of Veterinary Medicine, University of Teramo, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Malatesta
authors.forename: A
authors.initials: A
authors.lastname: Cuomo
authors.forename: M
authors.initials: M
authors.lastname: Marà
authors.forename: G
authors.initials: G
authors.lastname: Di Guardo
authors.forename: L
authors.initials: L
authors.lastname: Gentile
authors.forename: A
authors.initials: A
authors.lastname: Macolino
authors.forename: L
authors.initials: L
authors.lastname: Della Salda
mesh_terms: D000818:Animals; D005870:Giant Cell Tumors / Q000473:pathology / Q000601:surgery / Q000648:ultrastructure / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D046008:Lynx; D008297:Male; D013710:Tendons / Q000473:pathology*