Abstract
Annual skull radiographic screening of a 38-year-old female great Indian hornbill (Buceros bicornis) identified a small lesion in the rhinotheca rostral to the casque/beak interface. Excisional biopsy confirmed squamous cell carcinoma (SCC), with no invasion of tumor into the casque. Radiographs were repeated every 3 months. Treatment with oral meloxicam was initiated for its potential effect against carcinoma.2
Nine months after initial diagnosis radiographs revealed a 5-cm diameter mass in the rostral casque. The casque was nearly completely resected and the floor of the casque space was aggressively debrided. Histopathologic examination confirmed SCC. Topical treatment was begun using a previously described drug combination, OLCAT-005, to inhibit angiogenesis in cutaneous neoplasms, thereby inducing regression or suppressing tumor regrowth.1,3,4 Therapy consisted of equal parts by weight of imiquimod 5%, tretinoin 0.1%, calcipotriene 0.005%, diclofenac 3%, and hydrocortisone valerate 0.2%, mixed together and applied locally to the site three times a week. Meloxicam was discontinued.
Biopsy was negative after 5 months, and treatment was discontinued. The tumor remained in remission for 5 months until recurrent SCC was discovered by biopsy. Surgical debridement and topical therapy was repeated using the protocol above. At the time of submission of this abstract, >2 years since initial diagnosis and 15 months since initiation of treatment, the animal continues to receive topical antiangiogenesis treatment.
The authors conclude that early detection via annual skull radiographs, aggressive resection and debridement, and adjunct antiangiogenic treatment can produce long-term survival in management of SCC in great Indian hornbills.
Acknowledgments
The authors gratefully acknowledge the advice and support of Dr. Kathryn Gamble, Coraciiformes TAG veterinary advisor. Treatment of this bird could not have been done without the excellent assistance of the veterinary technicians, animal curators, and bird keepers of Zoo New England.
Literature Cited
1. Li, V.W., R.A. Ball, N. Vasan, W.W. Li. 2005. Antiangiogenic therapy for squamous cell carcinoma using combinatorial agents. J. Clin. Oncol. 23(16S):3032.
2. Liu, J.-F., S.-W. Zhang, G.G. Jamieson, G.-J. Zhu, T.-C. Wu, T.-N. Zhu, B.-E. Shan, and P.A. Drew. 2008. The effects of a COX-2 inhibitor meloxicam on squamous cell carcinoma of the esophagus in vivo. Int. J. Cancer. 122:1639–1644.
3. Wilson, R.W., E.E. Hammond, K.C. Gamble, V.W. Li, W. Li, T.N. Tully, M.A. Mitchell, C.J. Bonar, M.M. Garner, G. Mauldin, and R.F. Aguilar. 2004. Squamous cell carcinoma in a great Indian hornbill (Buceros bicornis). Proc. Am. Assoc. Zoo Vet. Annu. Meet. Pp. 376–381.
4. Zand, S., W.W. Li, V.W. Li. 2004. Efficacy of topical antiangiogenic therapy for basal cell and squamous cell carcinoma: A case series of 123 lesions. J. Am. Ac. Dermatol. 50:8.