This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
Follicular carcinoma of thyroid 
Select and explain. 
A. The most common thyroid cancer, B. Readily diagnosed thyroid cancer, C. Spreads through hematogenous route, D. Commonly multifocal
C: Spreads through hematogenous route
Answer: C: Spreads through hematogenous route 
Explanation: Follicular cancer of thyroid 20% of thyroid malignancies More common in iodine-deficient areas Clinical featuresTreatmentPredisposed by long-standing multinodular goiterHematogenous metastasis is more common than lymph nodal metastasis. Pulsatile secondaries may be seen in skull, ribs, pelvis. Malignancy is defined by the presence of capsular and vascular invasion. Hence FNAC cannot differentiate between follicular adenoma and carcinoma Follicular tumors>4 cm size are more likely to be malignant. Follow up can be done using I123 scan or by thyroglobulin estimation. Thyroglobulin levels in patients who have undergone total thyroidectomy should be below 2 ng/ml. Total thyroidectomyProphylactic nodal dissection is not needed because nodal involvement is infrequentIf nodal involvement is seen functional block dissection must be done. If FNAC shows follicular adenoma; lobectomy is enough because 80% of cases are benign. If the biopsy repo becomes positive for malignancy based on angio or capsular invasion Completion Total thyroidectomy must be done I131 therapyExternal beam RadiotherapyChemotherapy: Adriamycin and taxanes (Refer: Schwaz's Principles of Surgery, 9th edition, pg no: 1363-1365)