Which is the least common thyroid malignancy?

Ans. is 'd' i.e., Anaplastic carcinoma * Least common type of thyroid carcinoma is anaplastic type.* Most common type of thyroid carcinoma is papillary carcinoma (75%-85%) followed by follicular carcinoma (10-15%), medullary carcinoma (5%) and anaplastic carcinoma (<5%).