This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitreous and retina, Subject name: Ophthalmology
[{'content': 'A well-defined focal lesion in the cone of extraocular muscles of the eye with proptosis in a child. The diagnosis will be? \nSelect and explain. \nA. Cavernous hemangioma, B. Hemangioendothelioma, C. Capillary angioma, D. Retinoblastoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cavernous haemangioma is the commonest benign orbital tumour among adults. A tumour is usually located in the retrobulbar muscle cone. So, it presents as a slowly progressing unilateral axial proptosis in the second to fouh decade. It may occasionally compress the optic nerve without causing proptosis. Treatment. Surgical excision of a tumour is undeaken lateral orbitotomy approach. Since a tumour is well encapsulated, complete removal is generally possible. REFKhurana 4e pg: 394', 'role': 'assistant'}]