How are thyroid tumors classified?

4 types of cancers. There are 4 types of thyroid cancer (ca) thyroid follicular cells that make thyroid hormone can form papillary ca (cells look abnormal, best outpook), follicular ca (look normal, pushing outside tumor or into blood/lymph vessels, good outlook), and anaplastic ca (very abnormal, poor outlook). Parafollicular cells, or c-cells make calcitonin, and can form medullary ca (look abnormal, fair outlook).
Different ways. 1. Benign vs. Malignant there are many different types of both benign and malignant (cancerous) thyroid tumors. Cancers have their own staging systems which can be useful in prognosis, and depends on the size of the tumor, any lymph nodes involved, and cancer spread to distant sites.
Histology. Thyroid tumors are classified based on the appearance of a biopsy under the microscope (histology). There are benign tumors, adenomas, multi nodular goiters, malignant tumors papillary, follicular, Hurthle cell, medullary, and anaplastic, could also be metastatic tumor. Each of these behave differently and the treatments are different.