This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': 'Which of the following is not of prognostic significance to choroidal melanoma? \nSelect and explain. \nA. Presence of retinal detachment, B. Size of the tumour, C. Cytology of the tumor cells, D. Presence of extraocular extension', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Presence of retinal detachment Secondary non rhegmatogenous exudative retinal detachment is a common sign of choroidal melanoma and has no prognostic significanceQ. Choroidal Melanoma Melanoma of choroid is the most common primary intraocular tumor in adultsQ and accounts for 85% of uveal melanomas.', 'role': 'assistant'}]