Follicular Thyroid Carcinoma Workup
- Author: Luigi Santacroce, MD; Chief Editor: Jules E Harris, MD, FACP, FRCPC more...
Current guidelines from the National Comprehensive Cancer Network recommend that patients with thyroid nodules undergo measurement of thyroid-stimulating hormone (TSH) and ultrasound of the thyroid and central neck; ultrasound of the lateral neck may be considered. Patients with thyroid nodules and a low TSH level should have radioiodine imaging: if this study reveals an autonomously functioning (“hot”) nodule, the patient should be evaluated for thyrotoxicosis.
Patients with hypofunctional nodules, and those with a normal or elevated TSH level, should be considered for fine-needle aspiration biopsy (FNAB), based on clinical and sonographic features. A cytologist could experience difficulty in distinguishing some benign cellular adenomas from their malignant counterparts (ie, follicular and Hürthle cell adenomas from carcinomas). On final pathologic assessment, only about 20% of patients with an FNAB cytologic diagnosis of “suspicious for follicular neoplasm” will prove to have a follicular thyroid carcinoma.
A prognostic indicator of significant value may be ras genotyping by polymerase chain reaction (PCR) technique, which may help in the clinical and histologic reassessment of these tumors.
Determining the serum level of carcinoembryonic antigen (CEA) may be helpful; the reference value is less than 3 ng/dL. However, the implications of CEA elevation are not specific because CEA levels are elevated in several cancers, and many healthy people may have small amounts of CEA, especially pregnant women and heavy smokers.
Ultrasonography is the first imaging study that must be performed in any patient with suspected thyroid malignancy.
Ultrasonography is noninvasive and inexpensive, and it represents the most sensitive procedure for identifying thyroid lesions and determining the diameter of a nodule (2-3 mm). Ultrasonography is also useful to localize lesions when a nodule is difficult to palpate or is located deeply.
A study by Xing et al demonstrates that the strain ratio measurement of thyroid lesions, which is a fast standardized method for analyzing stiffness inside examined areas, can be used as an additional tool with B-mode ultrasonography and helps increase the diagnostic performance of the examination.
Ultrasonography can determine whether a lesion is solid or cystic and can detect the presence of calcifications. The rate of accuracy of ultrasonography in categorizing nodules as solid, cystic, or mixed is near 90%.
Ultrasonography may direct a fine-needle aspiration biopsy (FNAB).
Disadvantages of thyroid ultrasonography are that the test cannot distinguish benign nodules from malignant nodules, and it cannot be used to identify true cystic lesions.
Pulsed and power Doppler ultrasonography may provide important information about the vascular pattern and the velocimetric parameters. Such information can be useful preoperatively to differentiate malignant from benign thyroid lesions.
Prior to the introduction of FNAB, thyroid scintigraphy (or thyroid scanning) performed with technetium Tc 99m pertechnetate (99mTc) or radioactive iodine (I-131 or I-123) was the initial diagnostic procedure of choice in thyroid evaluation.
Thyroid scanning is not as sensitive or specific as FNAB in distinguishing benign nodules from malignant nodules.
The scintigraphy procedure performed with 99mTc has a high error rate because although 99mTc is trapped in the thyroid, as iodide is, it is not organified there. 99mTc has a short half-life and cannot be used to determine functionality of a thyroid nodule.
Radioactive iodine is trapped and organified in the thyroid and can be used to determine functionality of a thyroid nodule. Iodine-containing compounds and seafood interfere with any tests that use radioactive iodine. Scintigraphic images of the thyroid are acquired 20-40 minutes after IV administration of radionuclide. In more than 90% of cases, clearly benign nodules appear as hot because they are hyperfunctioning and have a high uptake of radionuclide and, physiologically, of iodine. Malignant nodules usually appear as cold nodules because they are not functioning.
Thyroid scanning is helpful and specific in localizing the tumor preoperatively and residual thyroid tissue immediately postoperatively. It also is used to follow-up for tumor recurrence or metastasis. Thyroid scanning could be useful in diagnosing thyroid tumors in patients with benign lesions (by FNAB) or solid lesions (by ultrasonography).
Integrated imaging, using 18F-FDG and coregistered total body PET and CT scan, seems to be effective in improving diagnostic accuracy in patients with iodine-negative differentiated thyroid carcinoma, allowing precise localization of the tumor tissue. In addition, image fusion by integrated PET/CT offers more information than side-by-side interpretation of single images obtained separately with CT and PET.
Chest radiography, CT scanning, and MRI usually are not used in the initial workup of a thyroid nodule, except in patients with clear metastatic disease at presentation. These tests are second-level diagnostic tools and are useful in preoperative patient assessment.
Perform indirect or fiberoptic laryngoscopy to evaluate airway and vocal cord mobility and to have preoperative documentation of any unrelated abnormalities.
On gross examination, FTC appears encapsulated and solitary and is often found in necrotic and/or hemorrhagic areas, as depicted in the images below.
Histologically, the lesion may be encapsulated and may demonstrate well-defined follicles containing colloid, making its distinction from follicular adenoma difficult. Examples of FTC are shown in the images below.
See the list below:
Histologic and cellular patterns of endocrine tumors do not allow diagnosis of carcinoma; therefore, this diagnosis is made by finding pseudocapsule and/or blood vessel invasion, not by cellular morphology.
High magnification of the abortive follicles may demonstrate atypia of the follicular epithelium and intervening stroma.
Thyrocytes are large and show an abnormal nuclear/cytoplasmic ratio with several mitoses.
Presence of colloid-rich follicles lined by flattened follicular cells that are occasionally accompanied by several histiocytes is maintained in a benign lesion.
Definitive diagnosis is often not possible with samples obtained from FNAB because accurate distinction between benign and malignant lesions cannot be made.
Because of the well-known role of the RAS-RAF-MEK-MAP kinase pathway in thyroid carcinogenesis, n-RAS expression may be evaluated to differentiate follicular and papillary cancer of the thyroid.
The accurate assessment of the proliferative grading and the extent of invasion have high prognostic value and are mandatory in every specimen.
The staging of well-differentiated thyroid cancers is related to age for the first and second stages but not related for the third and fourth stages.
In patients younger than 45 years, staging is as follows:
Stage I: Any T, any N, M0 (Cancer is in the thyroid only.)
Stage II: Any T, any N, M1 (Cancer has spread to distant organs.)
In patients older than 45 years, staging is as follows:
Stage I: T1, N0, M0 (Cancer is in the thyroid only and may be found in one or both lobes.)
Stage II: T2, N0, M0 and T3, N0, M0 (Cancer is in the thyroid only and is larger than 1.5 cm.)
Stage III: T4, N0, M0 and any T, N1, M0 (Cancer has spread outside the thyroid but not outside of the neck.)
Stage IV: Any T, any N, M1 (Cancer has spread to other parts of the body.)
See Thyroid Cancer Staging for more information.
A comparison study in 98 patients with follicular thyroid carcinoma concluded that the American Thyroid Association (ATA) staging system predicts recurrence rate and survival better than TNM staging. Hazard ratios were 4.67 with ATA staging versus 1.26 for TNM staging.
Perform complete assessment of thyroid function in any patient with thyroid lumps. In addition to TSH, measure thyroxine, triiodothyronine, and serum levels of thyroglobulin, calcium, and calcitonin.
levels above the reference range of thyroxine (T4; reference range, 4.5-12.5 mcg/dL), triiodothyronine (T3; reference range, 100-200 ng/dL), and TSH (reference range, 0.2-4.7 mIU/dL) may indicate thyroid cancer. Available studies are not specific for FTC.
TSH suppression test
Thyroid cancer is autonomous and does not require TSH for growth, whereas benign thyroid lesions do. Therefore, when exogenous thyroid hormone feeds back to the pituitary to decrease the production of TSH, thyroid nodules that continue to enlarge are likely to be malignant. However, consider that 15-20% of malignant nodules are suppressible.
Preoperatively, the test is useful for patients with nontoxic solitary benign nodules and for women with repeated inconclusive test results. Postoperatively, the test also is useful in follow-up of FTC cases.
Fine-Needle Aspiration Biopsy
Fine-needle aspiration biopsy (FNAB) is considered the best first-line diagnostic procedure for a thyroid nodule; it is a safe and minimally invasive test. It is the required procedure for the diagnostic evaluation of the classic solitary thyroid nodule.
Local anesthesia is administered at the puncture site, and a 21G or 23G aspiration biopsy needle is guided into the mass. The nodule is held with the fingers of the left hand while a needle is introduced through the skin into the nodule with the right hand.
After aspiration, the material is placed on a glass slide, fixed with alcohol-acetone, and stained according to the technique of Papanicolaou.
Accuracy of FNAB is better than any other test for uninodular lesions. Sensitivity of the procedure is near 80%, specificity is near 100%, and errors can be diminished using ultrasound guidance. False-negative and false-positive results occur less than 6% of the time.
A cytologist could experience difficulty in distinguishing some benign cellular adenomas from their malignant counterparts (ie, follicular and Hürthle cell adenomas from carcinomas).
Thyroid biopsy could be performed using the classic Tru-Cut or Vim-Silverman needles, but FNAB is preferable. Patients comply best with FNAB.
[Guideline] NCCN Clinical Practice Guidelines in Oncology: Thyroid Carcinoma Version 1.2016. National Comprehensive Cancer Network. Available at http://www.nccn.org/professionals/physician_gls/PDF/thyroid.pdf. Accessed: July 15, 2016.
Asari R, Koperek O, Scheuba C, Riss P, Kaserer K, Hoffmann M, et al. Follicular thyroid carcinoma in an iodine-replete endemic goiter region: a prospectively collected, retrospectively analyzed clinical trial. Ann Surg. 2009 Jun. 249(6):1023-31. [Medline].
Johnson TL, Lloyd RV, Thor A. Expression of ras oncogene p21 antigen in normal and proliferative thyroidtissues. Am J Pathol. 1987 Apr. 127(1):60-5. [Medline].
Wright PA, Lemoine NR, Mayall ES, et al. Papillary and follicular thyroid carcinomas show a different pattern of ras oncogene mutation. Br J Cancer. 1989 Oct. 60(4):576-7. [Medline].
Karga H, Lee JK, Vickery AL Jr, Thor A, Gaz RD, Jameson JL. Ras oncogene mutations in benign and malignant thyroid neoplasms. J Clin Endocrinol Metab. 1991 Oct. 73(4):832-6. [Medline].
Bos JL. ras oncogenes in human cancer: a review. Cancer Res. 1989 Sep. 49(17):4682-9. [Medline].
McCabe CJ. Moving towards the use of targeted therapies in thyroid cancer. Nat Clin Pract Endocrinol Metab. 2008 Nov. 4(11):604-5. [Medline].
Williams MD, Zhang L, Elliott DD, et al. Differential gene expression profiling of aggressive and nonaggressive follicular carcinomas. Hum Pathol. 2011 Sep. 42(9):1213-20. [Medline]. [Full Text].
Cancer Facts & Figures 2016. American Cancer Society. Available at http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-047079.pdf. Accessed: July 15, 2016.
Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet. 2008 Feb 16. 371(9612):569-78. [Medline].
Handkiewcz-Junak D, Banasik T, Kolosza Z, Roskosz J, Kukulska A, Puch Z. Risk of malignant tumors in first-degree relatives of patients with differentiated thyroid cancer -- a hospital based study. Neoplasma. 2006. 53(1):67-72. [Medline].
Williams ED, Abrosimov A, Bogdanova T, et al. Thyroid carcinoma after Chernobyl latent period, morphology and aggressiveness. Br J Cancer. 2004 Jun 1. 90(11):2219-24. [Medline].
Zengi A, Karadeniz M, Erdogan M, et al. Does chernobyl accident have any effect on thyroid cancers in Turkey? Aretrospective review of thyroid cancers from 1982 to 2006. Endocr J. 2008 May. 55(2):325-30. [Medline].
Ito Y, Uramoto H, Funa K, Yoshida H, Jikuzono T, Asahi S. Delta Np73 expression in thyroid neoplasms originating from follicular cells. Pathology. 2006 Jun. 38(3):205-9. [Medline].
Xing P, Wu L, Zhang C, et al. Differentiation of benign from malignant thyroid lesions: calculation of the strain ratio on thyroid sonoelastography. J Ultrasound Med. 2011 May. 30(5):663-9. [Medline].
Miyakawa M, Onoda N, Etoh M, et al. Diagnosis of thyroid follicular carcinoma by the vascular pattern and velocimetric parameters using high resolution pulsed and power Doppler ultrasonography. Endocr J. 2005 Apr. 52(2):207-12. [Medline].
Palmedo H, Bucerius J, Joe A, Strunk H, Hortling N, Meyka S. Integrated PET/CT in differentiated thyroid cancer: diagnostic accuracy and impact on patient management. J Nucl Med. 2006 Apr. 47(4):616-24. [Medline].
Hassan A, Khalid M, Riaz S, Nawaz MK, Bashir H. Follicular Thyroid Carcinoma: Disease Response Evaluation Using American Thyroid Association Risk Assessment Guidelines. Eur Thyroid J. 2015 Dec. 4 (4):260-5. [Medline]. [Full Text].
Meadows KM, Amdur RJ, Morris CG, Villaret DB, Mazzaferri EL, Mendenhall WM. External beam radiotherapy for differentiated thyroid cancer. Am J Otolaryngol. 2006 Jan-Feb. 27(1):24-8. [Medline].
Bikas A, Kundra P, Desale S, Mete M, O'Keefe K, Clark BG, et al. Phase 2 clinical trial of sunitinib as adjunctive treatment in patients with advanced differentiated thyroid cancer. Eur J Endocrinol. 2016 Mar. 174 (3):373-80. [Medline].
Nixon IJ, Ganly I, Patel SG, Palmer FL, Whitcher MM, Tuttle RM, et al. Thyroid lobectomy for treatment of well differentiated intrathyroid malignancy. Surgery. 2012 Apr. 151(4):571-9. [Medline].
Lee S, Ryu HR, Park JH, et al. Excellence in robotic thyroid surgery: a comparative study of robot-assisted versus conventional endoscopic thyroidectomy in papillary thyroid microcarcinoma patients. Ann Surg. 2011 Jun. 253(6):1060-6. [Medline].
Brassard M, Borget I, Edet-Sanson A, et al. Long-term follow-up of patients with papillary and follicular thyroid cancer: a prospective study on 715 patients. J Clin Endocrinol Metab. 2011 May. 96(5):1352-9. [Medline].
Sisson JC, Freitas J, McDougall IR, et al. Radiation safety in the treatment of patients with thyroid diseases by radioiodine 131I : practice recommendations of the American Thyroid Association. Thyroid. 2011 Apr. 21(4):335-46. [Medline].
Carling T, Udelsman R. Thyroid Tumors. DeVita VT Jr, Lawrence TS, Rosenberg SA. DeVita, Hellman, and Rosenberg's Cancer: Principles and Practice of Oncology. 9th. Philadelphia: Lippincott Williams & Wilkins; 2011. 1457-1472.
Huang SC, Wu VC, Lin SY, Sheu WH, Song YM, Lin YH, et al. Factors related to clinical hypothyroid severity in thyroid cancer patients after thyroid hormone withdrawal. Thyroid. 2009 Jan. 19(1):13-20. [Medline].
Mallick U, Harmer C, Yap B, Wadsley J, Clarke S, Moss L, et al. Ablation with low-dose radioiodine and thyrotropin alfa in thyroid cancer. N Engl J Med. 2012 May 3. 366(18):1674-85. [Medline].
Ríos A, Rodríguez JM, Ferri B, Martínez-Barba E, Torregrosa NM, Parrilla P. Prognostic factors of follicular thyroid carcinoma. Endocrinol Nutr. 2014 Aug 21. [Medline].
Sugino K, Ito K, Nagahama M, et al. Prognosis and prognostic factors for distant metastases and tumor mortality in follicular thyroid carcinoma. Thyroid. 2011 Jul. 21(7):751-7. [Medline].
Hari CK, Kumar M, Abo-Khatwa MM, Adams-Williams J, Zeitoun H. Follicular variant of papillary carcinoma arising from lingual thyroid. Ear Nose Throat J. 2009 Jun. 88(6):[Medline].
Arnaldi LA, Borra RC, Maciel RM, Cerutti JM. Gene expression profiles reveal that DCN, DIO1, and DIO2 are underexpressed in benign and malignant thyroid tumors. Thyroid. 2005 Mar. 15(3):210-21. [Medline].
Baloch ZW, LiVolsi VA. Fine-needle aspiration of the thyroid: today andtomorrow. Best Pract Res Clin Endocrinol Metab. 2008 Dec. 22(6):929-39. [Medline].
Cameselle-Teijeiro J, Pardal F, Eloy C, Ruiz-Ponte C, Celestino R, Castro P, et al. Follicular thyroid carcinoma with an unusual glomeruloid pattern of growth. Hum Pathol. 2008 Oct. 39(10):1540-7. [Medline].
Castro P, Eknaes M, Teixeira MR, et al. Adenomas and follicular carcinomas of the thyroid display two major patterns of chromosomal changes. J Pathol. 2005 Jul. 206(3):305-11. [Medline].
Chao TC, Lin JD, Chen MF. Surgical treatment of thyroid cancers with concurrent graves disease. Ann Surg Oncol. 2004 Apr. 11(4):407-12. [Medline].
Clark JR, Lai P, Hall F, et al. Variables predicting distant metastases in thyroid cancer. Laryngoscope. 2005 Apr. 115(4):661-7. [Medline].
Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL, Mandel SJ. Management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2006 Feb. 16(2):109-42. [Medline].
D'Avanzo A, Treseler P, Ituarte PH, et al. Follicular thyroid carcinoma: histology and prognosis. Cancer. 2004 Mar 15. 100(6):1123-9. [Medline].
Di Cristofaro J, Marcy M, Vasko V, Sebag F, Fakhry N, Wynford-Thomas D. Molecular genetic study comparing follicular variant versus classic papillary thyroid carcinomas: association of N-ras mutation in codon 61 with follicular variant. Hum Pathol. 2006 Jul. 37(7):824-30. [Medline].
Durante C, Haddy N, Baudin E, Leboulleux S, Hartl D, Travagli JP. Long-term outcome of 444 patients with distant metastases from papillary and follicular thyroid carcinoma: benefits and limits of radioiodine therapy. J Clin Endocrinol Metab. 2006 Aug. 91(8):2892-9. [Medline].
Eszlinger M, Krohn K, Kukulska A, et al. Perspectives and limitations of microarray-based gene expression profiling of thyroid tumors. Endocr Rev. 2007. 28(3):322-38. [Medline].
Faquin WC. The thyroid gland: recurring problems in histologic and cytologic evaluation. Arch Pathol Lab Med. 2008 Apr. 132(4):622-32. [Medline].
Farahati J, Geling M, Mader U, et al. Changing trends of incidence and prognosis of thyroid carcinoma in lower Franconia, Germany, from 1981-1995. Thyroid. 2004 Feb. 14(2):141-7. [Medline].
Fernandes JK, Day TA, Richardson MS, Sharma AK. Overview of the management of differentiated thyroid cancer. Curr Treat Options Oncol. 2005 Jan. 6(1):47-57. [Medline].
Fryknäs M, Wickenberg-Bolin U, Göransson H, Gustafsson MG, Foukakis T, Lee JJ. Molecular markers for discrimination of benign and malignant follicular thyroid tumors. Tumour Biol. 2006. 27(4):211-20. [Medline].
Giorgadze TA, Baloch ZW, Pasha T, Zhang PJ, Livolsi VA. Lymphatic and blood vessel density in the follicular patterned lesions of thyroid. Mod Pathol. 2005 Nov. 18(11):1424-31. [Medline].
Gosnell JE, Sackett WR, Sidhu S, et al. Minimal access thyroid surgery: technique and report of the first 25 cases. ANZ J Surg. 2004 May. 74(5):330-4. [Medline].
Gyory F, Balazs G, Nagy EV. Differentiated thyroid cancer and outcome in iodine deficiency. Eur J Surg Oncol. 2004 Apr. 30(3):325-31. [Medline].
Hall P, Adami HO. Thyroid Cancer. Adami HO, Hunter D, Trichopoulos D. eds. Textbook of Cancer Epidemiology. 2nd edition. Oxford University Press; 2008. 504-519.
Ilias I, Alevizaki M, Lakka-Papadodima E, Koutras DA. Differentiated thyroid cancer in Greece: 1963-2000. Relation to demographic andenvironmental factors. Hormones. 2002 Jul-Sep. 1(3):174-8. [Medline].
Kaya H, Barbaros U, Erbil Y, Bozbora A, Kapran Y, Aral F, et al. Metastatic thyroid carcinoma. N Z Med J. 2005 Oct 28. 118(1224):U1705. [Medline].
Kebebew E, Clark OH. Differentiated thyroid cancer: "complete" rational approach. World J Surg. 2000 Aug. 24(8):942-51. [Medline].
Kondo T, Ezzat S, Asa SL. Pathogenetic mechanisms in thyroid follicular-cell neoplasia. Nat Rev Cancer. 2006 Apr. 6(4):292-306. [Medline].
Kuijt WJ, Huang SA. Children with differentiated thyroid cancer achieve adequate hyperthyrotropinemia within 14 days of levothyroxine withdrawal. J Clin Endocrinol Metab. 2005 Nov. 90(11):6123-5. [Medline].
Kushwaha RA, Verma SK, Mahajan SV. Endobronchial metastasis of follicular thyroid carcinoma presenting as hemoptysis: a case report. J Cancer Res Ther. 2008. (1):44-5. [Medline].
Lerma E, Mora J. Telomerase activity in "suspicious" thyroid cytology. Cancer. 2005 Dec 25. 105(6):492-7. [Medline].
Lin JD, Chao TC. Follicular thyroid carcinoma: From diagnosis to treatment. Endocr J. 2006 Aug. 53(4):441-8. [Medline].
Mazzaferri EL, Robbins RJ, Spencer CA, et al. A consensus report of the role of serum thyroglobulin as a monitoring method for low-risk patients with papillary thyroid carcinoma. J Clin Endocrinol Metab. 2003 Apr. 88(4):1433-41. [Medline].
Muresan MM, Olivier P, Leclère J, et al. Bone metastases from differentiated thyroid carcinoma. Endocr Relat Cancer. 2008 Mar. 15(1):37-49. [Medline].
Ogawa Y, Sugawara T, Seki H, Sakuma T. Thyroid follicular carcinoma metastasized to the lung, skull, and brain 12 years after initial treatment for thyroid gland--case report. Neurol Med Chir (Tokyo). 2006 Jun. 46(6):302-5. [Medline].
Pacini F, Schlumberger M, Harmer C, Berg GG, Cohen O, Duntas L. Post-surgical use of radioiodine (131I) in patients with papillary and follicular thyroid cancer and the issue of remnant ablation: a consensus report. Eur J Endocrinol. 2005 Nov. 153(5):651-9. [Medline].
Reiners C, Farahati J. 131I therapy of thyroid cancer patients. Q J Nucl Med. 1999 Dec. 43(4):324-35. [Medline].
Riesco-Eizaguirre G, Santisteban P. New insights in thyroid follicular cell biology and its impact in thyroid cancer therapy. Endocr Relat Cancer. 2007 Dec. 14(4):957-77. [Medline].
Robbins RJ, Wan Q, Grewal RK, Reibke R, Gonen M, Strauss HW, et al. Real-time prognosis for metastatic thyroid carcinoma based on 2-[18F]fluoro-2-deoxy-D-glucose-positron emission tomography scanning. J Clin Endocrinol Metab. 2006 Feb. 91(2):498-505. [Medline].
Ronckers CM, McCarron P, Engels EA, Ron E. New Malignancies Following Cancer of the Thyroid and Other Endocrine Glands. Curtis RE, Freedman DM, Ron E, Ries LAG, Hacker DG, Edwards BK, Tucker MA, Fraumeni JF Jr. New Malignancies Among Cancer Survivors: SEER Cancer Registries, 1973-2000. Bethesda, MD: NIH Publ. No. 05-5302; 2006. 375-395. [Full Text].
Ruschenburg I, Vollheim B, Stachura J, Cordon-Cardo C, Korabiowska M. Analysis of DNA mismatch repair gene expression and mutations in thyroid tumours. Anticancer Res. 2006 May-Jun. 26(3A):2107-12. [Medline].
Sarquis MS, Weber F, Shen L, et al. High frequency of loss of heterozygosity in imprinted, compared with nonimprinted, genomic regions in follicular thyroid carcinomas and atypical adenomas. J Clin Endocrinol Metab. 2006. 91:262-9. [Medline]. [Full Text].
Savin S, Cvejic D, Isic T, Paunovic I, Tatic S, Havelka M. The efficacy of the thyroid peroxidase marker for distinguishing follicular thyroid carcinoma from follicular adenoma. Exp Oncol. 2006 Mar. 28(1):70-4. [Medline].
Schmitt TS, Elte JW, Rietveld AP, van Zaanen HC, Castro Cabezas M. Bone metastasis of a follicular thyroid carcinoma originated in a toxic multinodular goiter. Eur J Intern Med. 2008 Nov. 19(7):e64-6. [Medline].
Siassakos D, Gourgiotis S, Moustafellos P, et al. Thyroid microcarcinoma during thyroidectomy. Singapore Med J. 2008 Jan. 49(1):23-5. [Medline].
Suster S. Thyroid tumors with a follicular growth pattern: problems in differential diagnosis. Arch Pathol Lab Med. 2006 Jul. 130(7):984-8. [Medline].
Ulger Z, Karaman N, Piskinpasa SV, Niksarlioglu YO, Kilickap S, Erman M. Endobronchial metastasis of thyroid follicular carcinoma. J Natl Med Assoc. 2006 May. 98(5):803-6. [Medline].
Vasko VV, Gaudart J, Allasia C, et al. Thyroid follicular adenomas may display features of follicular carcinoma and follicular variant of papillary carcinoma. Eur J Endocrinol. 2004 Dec. 151(6):779-86. [Medline].