Clinical Take Home: Iris darkening in cats - benign melanosis or malignant melanoma?

Iris melanoma in cats typically presents as diffuse iris darkening (Feline Diffuse Iris Melanoma, FDIM) rather than a focal pigmented mass. This can lead to difficulties in diagnosis because iris darkening is also seen in benign iris melanosis, a progressive but harmless iris pigmentation which is seen commonly in older cats. Differentiation of FDIM from benign iris melanosis is important because the former carries a guarded prognosis, with metastatic rates of 19%-63% reported. Whilst definitive diagnosis can only be achieved by histopathological examination of iris tissue, there are some ‘clinical markers’ seen in FDIM that we can use to point towards a diagnosis and which can be helpful in deciding how to manage the case. This short webinar will summarise: 1. The differential diagnosis for iris darkening in cats 2. Common clinical markers of FDIM 3. Management options and prognosis