Skip to Main Content

INTRODUCTION

Epidemiology

| Download (.pdf) | Print
Epidemiology
Incidence:

Estimated U.S. incidence in 2020: 52,890 (male: 12,720; female: 40,170)

Estimated new cases: 15.8 per 100,000 persons (based on 2012–2016 cases)

Deaths: Estimated U.S. deaths in 2020: 2,180
  • One of the few cancers that had increased in incidence over the past several years primarily due to the increased detection of occult papillary thyroid carcinomas on incidental screening techniques. The incidence plateaued from 2014 to 2015 and slowly declines starting from 2016

  • Mainly affects young people. Nearly 2 of 3 cases are found in people between the ages of 20 and 55 years

Surveillance, Epidemiology and End Results (SEER) Program, available from http://seer.cancer.gov [accessed in 2020]

Pathology

| Download (.pdf) | Print
Pathology
Epithelial (Differentiated) Carcinomas Incidence Other Cell Types Incidence
Papillary carcinomas 85% Medullary carcinoma <5%
Classic papillary (75) Anaplastic carcinomas 2%
Follicular variant (15) Lymphoma Very rare
Tall cell variant (4) Angiomatoid neoplasms Very rare
Columnar cell variant (<1) Mucoepidermoid carcinomas Very rare
Diffuse sclerosing variant (3) Malignant adult thyroid teratomas Very rare
Oxyphilic (Hürthle cell) variant (2) Carcinomas with thymic features Very rare
Follicular carcinomas 2–5% Paragangliomas Very rare
Classic follicular (76)    
Oxyphilic (Hürthle cell) variant (20)    
Insular carcinoma (4)    

Fagin JA et al. N Engl J Med 2016;375:1054–1067

Fagin JA et al. N Engl J Med 2016;375:2307 

LiVolsi VA. Surgical Pathology of the Thyroid. Philadelphia, PA: WB Saunders, 1990

 

Papillary thyroid cancer (PTC)

  1. Develops from thyroid follicular cells

  2. Usually found in 1 lobe; only 10–20% appear in both lobes

  3. Lymph node metastases are more frequent than distant metastases

  4. Mutations in BRAF V600E (T1799A) occurs in 6–80% of patients

  5. Recently, encapsulated noninvasive (ie, no signs of vascular or tumor capsule invasiveness) follicular variants of PTC have been reclassified as a benign entity and renamed “noninvasive follicular thyroid neoplasms with papillary-like nuclear features,” thereby significantly reducing the number of patients who are considered to have thyroid cancer

 

Nikiforov YE et al. JAMA Oncol 2016;2:1023–1029

 

Follicular thyroid cancer (FTC)

  1. Develops from the follicular cells in the normal thyroid

  2. Mutations of codon 61 of N-RAS (N2) have been reported in as many as 19% of FTCs. Distant metastases are more frequent than lymph node metastases, namely in FTC with extensive vascular invasion (up to 46%)

 

Grani G et al. Lancet Diabetes Endocrinol 2018;6:500–514

 

Hürthle cell carcinoma

  1. Usually assumed to be a variant of FTC, has been recognized as a separate entity in the last WHO classification

  2. Both lymph node and distant metastases are frequent in Hürthle cell carcinoma

 

Medullary thyroid cancer (MTC)

  1. Accounts for <5% of thyroid cancers

  2. Develops in the C cells of the thyroid

  3. Occurs in a familial form as multiple endocrine neoplasia type 2 (MEN 2A and MEN 2B2) and as a sporadic form (~80% of cases)

  4. Germline mutations in the RET (REarranged during Transfection) ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.