This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine, Subject name: Pathology
[{'content': 'Brown tumor of bone is seen in - \nSelect and explain. \nA. Hyperparathyroidism, B. Hypoparathyroidism, C. Hypo-thyroidism, D. Hyperthyroidism', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Hyperparathyroidism(Ref: R 9th/pg 1102)Skeletal Abnormalities in Hyperparathyroidism:*Osteoporosis- cortical bone more severely involved than medullary bone*Brown tumors: brown colour- due to increased vascularity, hemorrhage & hemosiderin deposition*Osteitisfibrosacystica (von Recklinghausen disease of bone)', 'role': 'assistant'}]