Thyroid cancer

For patient information click here Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Michael Maddaleni, B.S.; Ammu Susheela, M.D. [2]

Overview

Thyroid cancer refers to any of four kinds of tumors of the thyroid gland; Papillary, follicular, medullary and anaplastic. Papillary and follicular tumors are the most common and usually are benign. They grow slowly, may recur, but are generally not fatal in patients under 45 years of age. Medullary and anaplastic tumors are malignant. Medullary tumors have a good prognosis if restricted to the thyroid gland and a poorer prognosis if metastasis occurs. Anaplastic tumors are fast-growing and respond poorly to therapy. Thyroid nodule are diagnosed by ultrasound guided fine needle aspiration or frequently by thyroidectomy (surgical removal and subsequent histological examination). As the thyroid cancer can uptake iodine, radioactive iodine is a commonly used modality in thyroid carcinomas. However, it is followed by TSH suppression by thyroxine therapy.

Classification

Thyroid cancers can be classified according to their pathological characteristics. The following variants can be distinguished (distribution over various subtypes may show regional variation):