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
Which of the following is not a histological variant of thyroid neoplasm? 
Select and explain. 
A. Follicular, B. merkel cell, C. Insular, D. Anaplastic
B: merkel cell
Answer: B: merkel cell 
Explanation: Poorly differentiated thyroid cancer (DTC) describes a lesion that previously was known as "insular" thyroid cancer. Poorly DTC may be thought of as occupying a middle ground between DTC and ATC (anaplastic thyroid cancer), which is completely dedifferentiated Merkel-cell carcinoma is a rare and aggressive skin cancer Source : Sabiston 20th edition Pg : 910