papillary thyroid carcinoma
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Etiology
- most likely tumor to occur as a result of previous radiation to the head & neck
- may occur 30-40 years post-radiation exposure[3]
- familial component of risk[4]
Epidemiology
- most common thyroid cancer (75-85%)
- most commonly occurs in the 3rd to 5th decade of life
- female/male predominance of 3/1
- papillary carcinomas are incidentally found in up to 1/3 of routine autopsies
Pathology
- 50% present with lymph node involvement, 5% with distant metastases
- tumors may range in size up to 10 cm in diameter
- all papillary carcinomas have branching papillae witha fibrovascular stalk covered with multiple layers of cuboidal epithelial cells
- tumors may have both papillary & follicular morphology
- an encapsulated variant is described, but most papillary carcinomas are not encapsulated
- 20-30% of papillary carcinomas are associated with translocations involving the tyrosine kinase domain of the RET proto-oncogene & the papillary thyroid carcinoma gene (PTC)
- features of papillary carcinomas:
- hypochromatic 'empty' nuclei (orphan Annie eyes) nuclear grooves
- eosinophilic intranuclear inclusions representing invaginations of cytoplasm
- Psammoma bodies, usually within the cores of papillae, sometimes surrounded by calcific lamellations.
- papillary thyroid carcinoma arises from thyroid follicular cells[2]
Genetics
- familial component of risk[4]
- chromosomal translocation t(10;12)(q11;p13) involving ERC1 & RET associated with thyroid papillary carcinoma
- a chromosomal translocation t(1;3)(q21;q11) involving TFG with NTRK1 may be a cause of thyroid papillary carcinoma
- chromosomal translocation t(7;10)(q32;q11) involving RET with TIF1/TRIM24 generates the TIF1/RET (PTC6) oncogene
- chromosomal translocation t(8;10)(p21.3;q11.2) involving PCM1 with RET is found in thyroid papillary carcinoma the translocation links the protein kinase domain of RET to the major portion of PCM1
- chromosomal rearrangement involving TPM3 with NTRK1 may be a cause of thyroid papillary carcinoma
- chromosomal rearrangement involving TPR may be a cause of thyroid papillary carcinoma
- chromosomal inversion inv(10)(q11.2;q11.2) generates the RET/NCOA4 (PTC3) oncogene
- other implicated genes GADD45GIP1, PDGFC, TSHR, BRAF
Clinical manifestations
- uncommonly papillary carcinomas produce mild to moderate thyrotoxicosis
Laboratory
- serum thyroglobulin may be used as a marker for residual or recurrent disease
- PCR for BRAF mutation from fine-needle aspiration
Diagnostic procedures
- fine-needle aspiration (FNA)
- thyroid nodules > 1 cm
- analyze aspirate for BRAF mutation when diagnosis is indeterminate (specific for papillary thyroid carcinoma)[2]
Radiology
- radiolabeled iodine uptake
- more differentiated lesions may take-up radiolabeled iodine
Management
- tumors < 1.5 cm in diameter in patients > 50 years of age (low risk) may be followed by active surveillance[5]
- total thyroidectomy with lymph node dissection
- radio-iodine ablation of remnant thyroid tissue 4-6 weeks following surgery
- prognosis
- good, 98% 5 year survival[2]
- cumulative incidence of tumor growth 12% at 5 years for low-risk tumors followed by active surveillance[5]
- poorer prognosis occurs with larger, more poorly differentiated tumors with extension outside of thyroid & in older individuals, particularly men
- multifocality associated with an increased risk of recurrence
- relapse occurs in 12% of patients with no evidence of residual disease after thyroidectomy[2]
- good, 98% 5 year survival[2]
- thyroid replacement with levothyroxine titrated to
- below the normal range*
- free thyroxine index &/or free T4 within normal range
- follow-up evaluation for recurrence requires
- discontinuation of levothyroxine
- allowing the serum TSH to rise
- measuring serum thyroglobulin as a marker for residual thyroid tissue
- family members, 1st & second degree relatives at higher risk for papllary thyoid carcinoma, 5 & 2-fold, respectively[4]
* thyroid follicular cells, the origin of papillary thyroid carcinoma, are TSH-responsive[2]
More general terms
Additional terms
References
- ↑ Cotran et al Robbins Pathologic Basis of Disease, 5th ed. W.B. Saunders Co, Philadelphia, PA 1994 pg 1137
- ↑ Jump up to: 2.0 2.1 2.2 2.3 2.4 2.5 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15, 16, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2009, 2012, 2018, 2022.
- ↑ Jump up to: 3.0 3.1 Solomon DH, in: UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 12-15, 2001
- ↑ Jump up to: 4.0 4.1 4.2 4.3 Oakley GM et al Establishing a Familial Basis for Papillary Thyroid Carcinoma Using the Utah Population Database. JAMA Otolaryngol. Head Neck Surg. October 03, 2013 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/24092278 <Internet> http://archotol.jamanetwork.com/article.aspx?articleid=1745509
- ↑ Jump up to: 5.0 5.1 5.2 Tuttle RM, Fagin JA, Minkowitz G et al Natural History and Tumor Volume Kinetics of Papillary Thyroid Cancers During Active Surveillance. JAMA Otolaryngol Head Neck Surg. Published online Aug 31, 2017 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/28859191 Free PMC Article <Internet> http://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2650803
Scharpf J Achieving Active Surveillance for Thyroid Cancer - Not a Euphemism for Watching a Ticking Time Bomb. JAMA Otolaryngol Head Neck Surg. Published online Aug 31, 2017 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/28859186 <Internet> http://jamanetwork.com/journals/jamaotolaryngology/article-abstract/2650802 - ↑ Jump up to: 6.0 6.1 Kim H, Kwon H, Moon BI et al Association of Multifocality With Prognosis of Papillary Thyroid Carcinoma. A Systematic Review and Meta-analysis. JAMA Otolaryngol Head Neck Surg. 2021. August 19. PMID: https://www.ncbi.nlm.nih.gov/pubmed/34410321 https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2783466
Patient information
papillary thyroid carcinoma patient information