CASE REPORT: Retinoblastoma in the eye of a llama (Llama glama)

• Published in: Veterinary ophthalmology 2005-07, Vol.8 (4), p.287-290
• Main Authors: Fugaro, Michael N, Kiupel, Matti, Montiani-Ferreira, Fabiano, Hawkins, Jan F, Janovitz, Evan B
• Format: Article
• Language: English
• ISSN: 1463-5216; 1463-5224
• DOI: 10.1111/j.1463-5224.2005.00407.x

Animal studied: A 6-year-old, pregnant female llama experienced a 6-month history of epiphora, buphthalmos, and acute loss of vision in the left eye. The condition was unresponsive to topical antimicrobial and anti-inflammatory therapy and progressed to corneal rupture. Procedures: Transpalpebral enucleation was performed and an intraorbital silicone prosthesis was implanted. The eye was fixed in formalin and processed according to routine paraffin technique. Sections of a mass were immunohistochemically prepared routinely and stained for glial fibrillary acidic protein (GFAP), S-antigen, and rhodopsin. Results: Gross, histopathologic, and immunohistochemical analysis revealed a retinal tumor consistent with a retinoblastoma. The neoplastic tissue formed Flexner-Wintersteiner and Homer-Wright rosettes, originated from the retina, and demonstrated photoreceptor differentiation with S-antigen and rhodopsin expression. Neoplastic cells were negative for GFAP. Four years after enucleation, the llama showed no signs of recurrent neoplasia. Conclusions: This report describes the diagnosis and successful treatment of the first known retinoblastoma in a llama.