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
Brown tumor of bone is seen in - 
Select and explain. 
A. Hyperparathyroidism, B. Hypoparathyroidism, C. Hypo-thyroidism, D. Hyperthyroidism
A: Hyperparathyroidism
Answer: A: Hyperparathyroidism 
Explanation: 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)