Lateral canthal fibroma in a dog.

A 9-year-old castrated male pitbull dog was presented for evaluation of a subconjunctival swelling of 10 days duration. On ophthalmic examination, a subcutaneous mass was identified at the right lateral canthus. An excisional biopsy was performed, and histopathological analysis confirmed a diagnosis of a subcutaneous fibroma. Eleven months after surgical excision, the dog had no evidence of recurrence. Fibroma should be included in the differential diagnosis of rapidly enlarging eyelid masses.