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: Medicine
In hyperparathyroidism, all are seen except - 
Select and explain. 
A. Osteopetrosis, B. Osteoporosis, C. Cysts, D. Brown tumor
A: Osteopetrosis
Answer: A: Osteopetrosis 
Explanation: in hyperparathyroidism, osteoporosis occurs but no osteopetrosis in which the bone becomes harder ( Harrison 17 pg 2382)