Papillary thyroid cancer

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Papillary thyroid cancer
Classification and external resources
Papillary Carcinoma of the Thyroid.jpg
Papillary thyroid carcinoma.
ICD-10C73
ICD-9193
ICD-O:M8260/3
OMIM603744
MedlinePlus000331
eMedicinemed/2464
MeSHD013964
 
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Papillary thyroid cancer
Classification and external resources
Papillary Carcinoma of the Thyroid.jpg
Papillary thyroid carcinoma.
ICD-10C73
ICD-9193
ICD-O:M8260/3
OMIM603744
MedlinePlus000331
eMedicinemed/2464
MeSHD013964

Papillary thyroid cancer or papillary thyroid carcinoma[1] is the most common type of thyroid cancer,[2] representing 75 percent to 85 percent of all thyroid cancer cases.[1] It occurs more frequently in women and presents in the 20–55 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck.[3]

Markers[edit]

Thyroglobulin can be used as a tumor marker for well-differentiated papillary thyroid cancer.[4][5] HBME-1 staining may be useful for differentiating papillary carcinomas from follicular carcinomas; in papillary lesions it tends to be positive.[6]

Pathology[edit]

Although papillary carcinoma has a propensity to invade lymphatics, it is less likely to invade blood vessels.[14] These kinds of tumors are most commonly unencapsulated, and they have a high tendency to metastasize locally to lymph nodes, which may produce cystic structures near the thyroid that are difficult to diagnose because of the paucity of malignant tissue.[15][16] Furthermore, papillary tumors may metastasize to the lungs and produce a few nodules or the lung fields may exhibit a snowflake appearance throughout.

Other characteristics of the papillary carcinoma is that E.M. shows increased mitochondria, increased RER, as well as increased apical microvilli. Moreover, papillary carcinomas have an indolent growth, and 40 percent of cases spread out of the capsule.[17]

Associated mutations[edit]

Mutations associated with papillary thyroid cancer are mainly two forms of chromosomal translocation and one form of point mutation. These alterations lead to activation of a common carcinogenic pathway—the MAPK/ERK pathway.

Chromosomal translocations involving the RET proto-oncogene (encoding a tyrosine kinase receptor that plays essential roles in the development of neuroendocrine cells) located on chromosome 10q11 occur in approximately a fifth of papillary thyroid cancers. The fusion oncoproteins generated are termed RET/PTC proteins (ret/papillary thyroid carcinoma), and constitutively activate RET and the downstream MAPK/ERK pathway.[1] The frequency of ret/PTC translocations is significantly higher in papillary cancers arising in children and after radiation exposure.[1] The gene NTRK1 (encoding the TrkA receptor), located on chromosome 1q, is similarly translocated in approximately 5 percent to 10 percent of papillary thyroid cancers.[1]

Approximately a third to a half of papillary thyroid carcinomas harbor point mutations in the BRAF oncogene, also activating the MAPK/ERK pathway.[1] In those cases the BRAF mutations found were V600E mutation. After performing a multivariate analysis, it was found that the absence of tumor capsule was the only parameter associated (P=0.0005) with BRAF V600E mutation.[16] According to recent studies, papillary cancers carrying the common V600E mutation tend to have a more aggressive long term course. BRAF mutations are frequent in papillary carcinoma and in undifferentiated cancers that have developed from papillary tumors.

Diagnosis[edit]

Papillary thyroid carcinoma is usually discovered on routine examination as an asymptomatic thyroid nodule that appears as a neck mass. In some instances, the mass may have produced local symptoms. This mass is normally referred to a fine needle aspiration biopsy (FNA) for investigation. FNA accuracy is very high and it is a process widely used in these cases. Other investigation methods include ultrasound imaging and nuclear scan. The ultrasound is a useful test to distinguish solid from cystic lesions and to identify calcifications.[18] The thyroid ultrasound is also very effective to discover microcarcinomas, which refer to very small carcinomas (<1 cm).

Papillary thyroid carcinomas are also discovered when a hard nodule is found in multinodular goiter, when enlarged cervical lymph nodes are detected, or when there are unidentified metastatic lesions elsewhere in the body.[16] Expanding lesions found in the thyroid gland, especially if they are painful, should be examined as they may indicate the presence of papillary thyroid carcinoma. Other clinical signs that could indicate papillary thyroid are: fixation to the trachea, stony hardness, damage to recurrent laryngeal or cervical sympathetic nerves. Seventy five percent of the population will have these thyroid nodules, and the majority will always be benign.[19]

Chest x rays are not commonly performed. In cases of metastasis, some other tests are run to obtain sufficient information before a surgery. Such tests include the ultrasound and MRI of the neck as well as the CAT scanning. Other options that have shown good results in identifying tumors or related outcomes are the use of thallium-201 chloride, which helps identify metastatic tumor; gallium scan, which is helpful to visualize lymphomas; I-metaiodobenzylguanidine (MIBG) which has proven useful in imaging MTC; Tc-MIBI, which has been effective in detecting deposits of metastatic thyroid cancer; PET scans, which are also helpful for the imaging of metastatic disease. Chia et al. report that TSHR mRNA measured with FNA enhances the preoperative detection of cancer in patients with thyroid nodules, reducing unnecessary surgeries, and immediate postoperative levels can predict residual/metastatic disease.[16] Suspected lung metastases and/or miliary aspects at x-ray or CT can be diagnosed by cytology on a bronchoalveolar lavage specimen.[20]

Prognosis[edit]

Depending on source, the overall 5-year survival rate for papillary thyroid cancer is 96 percent[21] or 97 percent,[22] with a 10-year survival rate of 93 percent.[21]

For a more specific prognosis for individual cases, there are at minimum 13 known scoring systems for prognosis; among the more often used are:

MACIS[edit]

The MACIS system of estimating the prognosis of papillary thyroid cancer was developed by Clive S. Grant at the Mayo Clinic, and was based on careful evaluation of a large group of patients. It is probably the most reliable staging method available.[24]

It assigns scores to the main factors involved, and uses the sum of this score to calculate the prognosis:

Factors[24]Score[24]
Distant Metastasis: spread of the cancer to areas outside the neckYes3
No0
Age at the time the tumor was discoveredLess than 39 years3.1
Over 40 years0.08 x age
Invasion into surrounding areas of the neck as seen by the naked eyeYes1
No0
Completeness of surgical resection (or removal) of the tumorIncomplete1
Complete0
Size of the tumor0.3 x size in cm
Sum of MACIS score[24]20 yr Survival[24]
< 6.099%
6.0 - 6.9989%
7.0 - 7.9956%
> 8.024%

Most patients fall into the low risk category (MACIS score less than 6.0) and are cured of the cancer at the time of surgery.[24]

Children with multiple lung metastases and/or a miliary aspect still have an excellent long-term prognosis if given adequate treatment.[20]

Stage[edit]

Based on overall cancer staging into stages I to IV, papillary thyroid cancer has a 5-year survival rate of 100 percent for stages I and II, 93 percent for stage III and 51 percent for stage IV.[25]

Treatment[edit]

Surgical treatment:

Arguments for total thyroidectomy are:

Thyroid total body scans are less reliable at finding recurrence than TG and ultrasound.

Papillary tumors tend to be more aggressive in patients over age 45. In such cases it might be required to perform a more extensive resection including portions of the trachea. Also, the sternocleidomastoid muscle, jugular vein, and accessory nerve are to be removed if such procedure allows apparently complete tumor resection. If a significant amount of residual tumor is left in the neck, external radiotherapy has been indicated and has proven useful especially in those cases when residual tumor does not take up radioiodine.

After surgical thyroid removal, the patient waits around 4–6 weeks to then have radioiodine therapy. This therapy is intended to both detect and destroy any metastasis and residual tissue in the thyroid. The treatment may be repeated 6–12 months after initial treatment of metastatic disease where disease recurs or has not fully responded.[26]

Patients are administered hormone replacement levothyroxine for life after surgery, especially after total thyroidectomy. Chemotherapy with cisplatin or doxorubicin has proven limited efficacy, however, it could be helpful for patients with bone metastases to improve their quality of life. Patients are also prescribed levothyroxine and radioiodine after surgery. Levothyroxine influences growth and maturation of tissues and it is involved in normal growth, metabolism, and development. In case of metastases, patients are prescribed antineoplastic agents which inhibit cell growth and proliferation and help in palliating symptoms in progressive disease.

After successful treatment, 35 percent of the patients may experience recurrence within a 40-year span. Also, patients may experience a high incidence of nodule metastasis, with 35 percent cases of cervical node metastases. Approximately 20 percent of patients will develop multiple tumors within the thyroid gland.[27]

Additional images[edit]

References[edit]

  1. ^ a b c d e f Chapter 20 in: Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K; Fausto, Nelson. Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7.  8th edition.
  2. ^ Hu MI, Vassilopoulou-Sellin R, Lustig R, Lamont JP "Thyroid and Parathyroid Cancers" in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (Eds) Cancer Management: A Multidisciplinary Approach. 11 ed. 2008.
  3. ^ Dinets A, Hulchiy M, Sofiadis A, Ghaderi M, Höög A, Larsson C, Zedenius J (2012). "Clinical, Genetic and Immunohistochemical Characterization of 70 Ukrainian Adult Cases with Post-Chornobyl Papillary Thyroid Carcinoma". Eur J Endocrinol 166: 1049–60. doi:10.1530/EJE-12-0144. PMC 3361791. PMID 22457234. 
  4. ^ Lin JD (2007). "Thyroglobulin and human thyroid cancer". Clin Chim Acta 388 (1–2): 15. doi:10.1016/j.cca.2007.11.002. PMID 18060877. 
  5. ^ Tuttle RM, Leboeuf R, Martorella AJ (2007). "Papillary thyroid cancer: monitoring and therapy". Endocrinol. Metab. Clin. North Am. 36 (3): 753–78, vii. doi:10.1016/j.ecl.2007.04.004. PMID 17673127. 
  6. ^ Papotti M, Rodriguez J, De Pompa R, Bartolazzi A, Rosai J (April 2005). "Galectin-3 and HBME-1 expression in well-differentiated thyroid tumors with follicular architecture of uncertain malignant potential". Mod. Pathol. 18 (4): 541–46. doi:10.1038/modpathol.3800321. PMID 15529186. 
  7. ^ "Papillary Carcinoma of Thyroid (Hi Pow)". University of Connecticut Health Center. Retrieved 2008-09-14. 
  8. ^ Yang GC, Liebeskind D, Messina AV (2001). "Ultrasound-guided fine-needle aspiration of the thyroid assessed by Ultrafast Papanicolaou stain: data from 1135 biopsies with a two- to six-year follow-up". Thyroid 11 (6): 581–89. doi:10.1089/105072501750302895. PMID 11442006. 
  9. ^ Escofet X, Khan AZ, Mazarani W, Woods WG (2007). "Lessons to be learned: a case study approach. Lateral aberrant thyroid tissue: is it always malignant?". J R Soc Health 127 (1): 45–6. doi:10.1177/1466424007073207. PMID 17319317. 
  10. ^ Shaha AR (2007). "TNM classification of thyroid carcinoma". World J Surg 31 (5): 879–87. doi:10.1007/s00268-006-0864-0. PMID 17308849. 
  11. ^ Harach HR, Franssila KO, Wasenius VM (1985). "Occult papillary carcinoma of the thyroid. A "normal" finding in Finland. A systematic autopsy study". Cancer 56 (3): 531–8. doi:10.1002/1097-0142(19850801)56:3<531::AID-CNCR2820560321>3.0.CO;2-3. PMID 2408737. 
  12. ^ Pakdaman MN, Rochon L, Gologan O, Tamilia M, Garfield N, Hier MP, Black MJ, Payne RJ (2008). "Incidence and histopathological behavior of papillary microcarcinomas: Study of 429 cases". Otolaryngol Head Neck Surg 139 (5): 718–22. doi:10.1016/j.otohns.2008.08.014. PMID 18984270. 
  13. ^ Woolner LB, Lemmon ML, Beahrs OH, Black BM, Keating FR (January 1960). "Occult papillary carcinoma of the thyroid gland: a study of 140 cases observed in a 30-year period". J. Clin. Endocrinol. Metab. 20: 89–105. doi:10.1210/jcem-20-1-89. PMID 13845950. 
  14. ^ "Thyroid, Papillary Carcinoma". Retrieved 2010-07-15. 
  15. ^ Grani, G; Fumarola, A (Jun 2014). "Thyroglobulin in Lymph Node Fine-Needle Aspiration Washout: A Systematic Review and Meta-analysis of Diagnostic Accuracy.". The Journal of clinical endocrinology and metabolism 99 (6): 1970–82. PMID 24617715. 
  16. ^ a b c d "The Thyroid and its Diseases". Retrieved 2010-07-15. 
  17. ^ "Papillary Carcinomas". Retrieved 2010-07-15. [dead link]
  18. ^ "Papillary Thyroid Carcinoma: An Overview". Archives of Pathology & Laboratory Medicine. 2006. Retrieved 2010-07-15. 
  19. ^ "Papillary Carcinoma Prognosis". Retrieved 2010-07-15. 
  20. ^ a b Vermeer-Mens, J. C. J.; Goemaere, N. N. T.; Kuenen-Boumeester, V.; De Muinck Keizer-Schrama, S. M. P. F.; Zwaan, C. M.; Devos, A. S.; De Krijger, R. R. (2006). "Childhood Papillary Thyroid Carcinoma with Miliary Pulmonary Metastases". Journal of Clinical Oncology 24 (36): 5788–5789. doi:10.1200/JCO.2006.08.8732. PMID 17179115.  edit [1]
  21. ^ a b Numbers from National Cancer Database in the US, from Page 10 in: Biersack, H-J; Grünwald, F (Eds) (2005). Thyroid Cancer. Berlin: Springer. ISBN 3-540-22309-6.  (Note: Book also states that the 14 percent 10-year survival for anaplastic thyroid cancer was overestimated)
  22. ^ Rounded up to nearest natural number from 96.7 percent as given by eMedicine > Thyroid, Papillary Carcinoma Author: Luigi Santacroce. Coauthors: Silvia Gagliardi and Andrew Scott Kennedy. Updated: Sep 28, 2010
  23. ^ "New York Thyroid Center: Prognosis Staging for Thyroid Cancer". Retrieved 2007-12-22. 
  24. ^ a b c d e f New York Thyroid Center > Thyroid cancer > Prognosis staging Retrieved on April 30, 2010
  25. ^ cancer.org > Thyroid Cancer By the American Cancer Society. In turn citing: AJCC Cancer Staging Manual (7th ed).
  26. ^ "Treatment". Retrieved 2010-07-15. 
  27. ^ "Papillary Thyroid Carcinoma". Retrieved 2010-07-15. [dead link]