This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
"Orphan Annie eye nuclei" is characteristic histologic feature of which of the following thyroid malignancy ? 
Select and explain. 
A. Papillary carcinoma of thyroid, B. Medullary carcinoma of thyroid, C. Anaplastic carcinoma of thyroid, D. Follicular carcinoma of thyroid
A: Papillary carcinoma of thyroid
Answer: A: Papillary carcinoma of thyroid 
Explanation: Orphan Annie nuclei is a characteristic intranuclear inclusion seen mainly in papillary carcinoma of thyroid. Ultrastructurally they are seen as membrane bound spheroidal masses of cytoplasm intruding into the nuclei. Intranuclear inclusions are less commonly seen in hyalinizing trabecular adenomas, medullary carcinoma, huhle cell carcinoma as well as anaplastic carcinoma.