<prompt> Brown Tumor is seen in:HypothyroidismHypehyroidismHypoparathyroidismHyperparathyroidism  <response>: Brown tumor is usually seen in excess osteoclastic activities, such as hyperparathyroidism. It is a repairative process rather than neoplastic. In hyperparathyroidism there is excess parathyroid hormone PTH secreted, which leads to excess calcium resorption from the bones leading to ostitis fibrosa cystica. Ref: Harrisons Principles of Internal Medicine, 17th Edition, Page 1765; Robbins Pathologic Basis of Disease, 8th Edition, Pages 1218, 1128. 