This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pathology
Brown tumor is seen in 
Select and explain. 
A. Hypehyroidism, B. Hypothyroidism, C. Hyperparathyroidism, D. Hypoparathyroidism
C: Hyperparathyroidism
Answer: C: Hyperparathyroidism 
Explanation: Primary hyperparathyroidism is a disease characterized by excessive secretion of parathormone which results in increased osteoclastic activity therby causing bone loss . The bone loss predisoses to microfractures and secondary hemorrhages that elicit an influx of macrophages and an ingrowth of reparative fibrous tissue, creating a mass of reactive tissue known as brown tumor . Ref: Robbins and cotrans 9e Pg 1102