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': 'Which of the following type of malignancy is associated with the characteristic Zellballen pattern on histopathology? \nSelect and explain. \nA. GIST, B. Astrocytoma, C. Carotid body tumor, D. Retinoblastoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Zellballen pattern refers to the nest-like clusters of uniform, round-to-polygonal chief cells surrounded by delicate richly vascular tissue and sustentacular cells. This histological pattern is a characteristic feature of carotid body paraganglioma.', 'role': 'assistant'}]