Concurrent iridociliary adenoma and haemorrhagic uveal cysts causing rapid intraocular mass progression in a dog

Abstract A 6‐year‐old, mixed‐breed dog was referred for evaluation of a red, non‐painful right eye. Examination revealed a well‐circumscribed, lobulated, reddish mass in the anterior chamber, initially presumed to be a benign haematocyst. Despite the non‐aggressive appearance and lack of pain or inflammation, the mass demonstrated rapid enlargement over a period of 3 months. Ocular ultrasonography identified a complex intraocular lesion with both cystic and solid components, and colour Doppler revealed internal vascularity, raising suspicion of neoplasia. Surgical enucleation was performed, and histopathology confirmed a diagnosis of non‐invasive iridociliary adenoma, accompanied by blood‐filled ciliary body cysts. The rapid progression was attributed primarily to haemorrhagic distension of the cystic structures. This case highlights the diagnostic challenge posed by overlapping features of benign cysts and neoplastic growth, and emphasises the value of repeat imaging and Doppler ultrasonography in guiding timely diagnosis and management of atypical intraocular lesions.