# Radiation Oncology/Thyroid/Workup

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| Thyroid: Main Page | Workup | Staging | Papillary and follicular | Medullary | Hurthle cell | Anaplastic | |

## Thyroid nodules

* 95% of palpable thyroid nodules in adults are benign.
* Prevalence is around 4% in the general population by palpation. Prevalence is 30-50% by ultrasound.
* FNA biopsy is the most reliable diagnostic test for a thyroid nodule. Can be positive for malignancy, negative, or indeterminate.
If positive for malignancy, should proceed to definitive treatment.
If negative, serial follow-up is recommended.
Indeterminate biopsies can be:
* Suspicious for papillary carcinoma: patients with biopsy suspicious have a high likelihood (82%) of having papillary carcinoma. Recommend total thyroidectomy.
* Suspicious for follicular or Hürthle cell carcinoma: Only 15-20% chance of invasive carcinoma. Usually proceed to thyroidectomy with frozen section analysis.
Reviews:
* PMID 12588078, 2003 — "Thyroid nodules." Welker MJ et al. Am Fam Physician. 2003 Feb 1;67(3):559-66.
Guidelines:
* Society of Radiologists in Ultrasound (2004)
** PMID 16304103 Full text -- "Management of thyroid nodules detected at US: Society of Radiologists in Ultrasound consensus conference statement." (Frates MC, Radiology. 2005 Dec;237(3):794-800.) -- 2004 consensus statement
** Solitary nodule:
*** Microcalcifications - strongly consider U/S guided FNA if ≥ 1 cm
*** Solid (or almost entirely solid) or coarse calcifications - strongly consider U/S guided FNA if ≥ 1.5 cm
*** Mixed solid and cystic or almost entirely cystic with solid mural component - consider U/S guided FNA if ≥ 2 cm
*** None of the above, but substantial growth since prior U/S - consider U/S guided FNA
*** Almost entirely cystic and none of the above and no substantial growth (or no prior U/S) - U/S guided FNA probably unnecessary
** Multiple nodules - consider U/S guided FNA of one or more nodules on basis of criteria (in order listed) for solitary nodule
* AACE/AME Guidelines (2006) - Website PDF
** PMID 16596732 — "American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi medical guidelines for clinical practice for the diagnosis and management of thyroid nodules." (Endocr Pract. 2006 Jan-Feb;12(1):63-102.)
* ATA Guidelines - Website
** 2009: PMID 19860577 PDF — "Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer." (Cooper DS, Thyroid. 2009 Nov;19(11):1167-214.)

## Thyroid incidentalomas

Thyroid incidentalomas are thyroid nodules discovered incidentally by an imaging procedure (e.g. US or CT) performed for an unrelated incidcation.
Prevalence:
* PMID 15009911, 2004 — "Prevalence, clinical and ultrasonographic characteristics of thyroid incidentalomas."
* PMID 15840794, 2005 — "Rates of malignancy in incidentally discovered thyroid nodules evaluated with sonography and fine-needle aspiration."
Diagnosis:
* PMID 14678283, 2004 — "Ultrasonography-guided fine-needle aspiration of thyroid incidentaloma: correlation with pathological findings."
Reviews:
* PMID 15145242, 2004 — "Management of thyroid incidentalomas."

## Guidelines

    see Radiation Oncology/Thyroid/Guidelines
Management/Treatment:
* AACE/AAES Guidelines (2001) - Website PDF
** PMID 11430305 — "AACE/AAES medical/surgical guidelines for clinical practice: management of thyroid carcinoma. American Association of Clinical Endocrinologists. American College of Endocrinology." (Endocr Pract. 2001 May-Jun;7(3):202-20.)