This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
This thyroiditis is also known as "Painless Thyroiditis. 
Select and explain. 
A. Subacute lymphocytic, B. Dequervain's, C. Hashimoto, D. Riedel
A: Subacute lymphocytic
Answer: A: Subacute lymphocytic 
Explanation: . Subacute lymphocytic thyroiditis is a form of thyroiditis that is also known as silent thyroiditis or painless thyroiditis. Subacute lymphocytic thyroiditis may occur at any age and is more common in females. A variant of subacute lymphocytic thyroiditis occurs postpaum, postpaum thyroiditis. Both of these entities can be considered subtypes of Hashimoto&;s thyroiditis and have an autoimmune basis. Anti-thyroid antibodies are common in all three and the underlying histology is similar. This disorder should not be confused with de Quervain&;s thyroiditis which is another form of subacute thyroiditis.