Benign Giant Cell Tumour of Tendon Sheaths in a European Lynx ( Lynx lynx)

• Published in: Journal of Veterinary Medicine Series A
• Main Authors: Malatesta, D., Cuomo, A., Marà, M., Di Guardo, G., Gentile, L., Macolino, A., Della Salda, L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: Lynx; Lynx lynx lynx
• Online Access: http://dx.doi.org/10.1111/j.1439-0442.2005.00701.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1439-0442.2005.00701.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1439-0442.2005.00701.x

Summary 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 α ‐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.