This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neoplasia, Subject name: Pathology
[{'content': 'Most common vascular tumour in AIDS \nSelect and explain. \nA. Kaposi - sarcoma, B. Angiosarcoma, C. Lymphangioma, D. Lymphoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Kaposi - sarcoma) (256 - R) (164- Basic pathology 8th)* Patients with AIDS have a high incidence of certain tumours especially Kaposi-sarcoma, non hodgkins B-cell lymphoma, cervical cancer in women and anal cancer in men* Kaposi - sarcoma is a vascular tumour that is otherwise rare in US is the most common neoplasm in patients with AIDS* The lesion of kaposi sarcoma are characterised by the proliferation of spindle cells that express markers of both endothelial (vascular or lymphatic) and smooth muscle lineages. There is also a profusion of slit -like vascular spaces, suggests that the lesions may arise from primitive mesenchymal precursors of vascular channels', 'role': 'assistant'}]