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: Pathology
[{'content': 'True about myxoma is - \nSelect and explain. \nA. Mostly seen in left atrium, B. Can metastasize to other sites, C. Rarely recurs after removal, D. Most often seen in right atrium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cardiac myxomas\no Most common primary tumor of the adult heart.\no Benign neoplasms thought to arise from primitive multipotentmesenchymal cells.\no Familial syndromes associated with myxomas have activating mutations\xa0in the GNAS1 gene, encoding a\xa0subunit of G protein (Gsa) (in association\xa0with McCune-Albright syndrome) or null mutations\xa0in\xa0PRKARIA, encoding a regulatory subunit of a cyclic-AMP- dependent protein kinase (Carney complex).\no About 90% of myxomas arise in the atria, with a left-to-right ratio\xa0of approximately 4:1.', 'role': 'assistant'}]