This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Parathyroid Gland, Subject name: Medicine
All are true about hyperparathyroidism except? 
Select and explain. 
A. Solitary adenoma, B. Malignant, C. Thyroid malignancy, D. Parathyroid hyperplasia
C: Thyroid malignancy
Answer: C: Thyroid malignancy 
Explanation: Hyperparathyroidism is usually due to a solitary adenoma. It can also be due to MEN Type 1 which accounts for about 90% of parathyroid cancers, which do not include thyroid malignancies in the group of the multiple endocrine neoplasms. Parathyroid hyperplasia can also lead to hyperparathyroidism.