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Small Animal Section: No. 15TUMOURS OF THE EYELIDS IN DOGSThe majority of eyelid tumours are benign. They are always of cosmetic concern. These tumours may cause conjunctival and corneal irritation leading to epiphora, blepharospasm and corneal ulceration. Eyelid tumours that have a histologically malignant nature tend to be locally infiltrative, but rarely metastasise. Description and treatment of eyelid tumours in dogs Tarsal adenoma : This is the most common and benign tumour originating from the Meibomian gland. It presents as an outward “cauliflower” like growth from the eyelid margin. If the eyelid is everted, the affected gland can be visualised beneath the conjunctiva. They are not infiltrative, but may enlarge to involve the entire eyelid leading to corneal irritation, epiphora and / or lagophthalmos. Surgical removal is indicated. * Papilloma : Viral induced non-infiltrative tumour of the eyelid that may accompany oral papillomatosis. In young dogs treatment is usually not necessary because they usually regress spontaneously. Surgical removal is indicated when leading to corneal irritation.* Melanoma : Elevated pigmented tumour of the eyelid and eyelid margin. Melanocytomas are almost always benign and not infiltrative. They may enlarge to involve the entire eyelid leading to corneal irritation. Surgical removal is indicated. * Squamous cell carcinoma : Exposure to high levels of ultraviolet light and unpigmented eyelids are predisposing factors for the development of squamous cell carcinomas. They present as ulcerative lesions of the eyelids or third eyelid. While local invasion of the surrounding tissue is its typical pattern of behaviour, metastasis may occur late in the disease. The treatment of choice for eyelid squamous cell carcinomas is repeated (2 – 4 times) local injection with chemotherapeutic drugs, for example carboplatin or cisplatin. Treatment of choice for squamous cell carcinomas of the third eyelid is partial or complete resection of the third eyelid, depending on the size and position of the tumour. Haemangioma / haemangiosarcoma : These are relatively common tumours of the third eyelid, with haemangiomas being more prevalent. Exposure to high levels of ultraviolet light is a predisposing factor for the development of these tumours. Haemangiosarcomas are locally more invasive than haemangiomas, but neither of these tumours is likely to metastasise. Treatment of choice is partial or complete resection of the third eyelid. *Surgery of eyelid tumours When less than a third of the eyelid is involved, the tumour can be removed by simple wedge excision and double layer eyelid closure. If more than a third of the eyelid is involved, more drastic surgical techniques are required to reconstruct the eyelid, for example H plasty, sliding z flaps or “bucket” handle techniques. These surgical procedures are technically difficult and magnification and microsurgical instruments are required. Compiled by: Dr Izak Venter For further information contact: VetPath Veterinary Pathologists
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